M Technical Report CERC-93-9 June 1993 Vee line US Army Corps of Engineers Waterways Experiment Station Annual Data Summary for 1991 CERC Field Research Facility Volume I: Main Text and Appendixes A and B by Michael W. Leffler, Clifford F. Baron, Brian L. Scarborough, Kent R. Hathaway Coastal Engineering Research Center Approved For Public Release; Distribution Is Unlimited LPR, ASO. AAS lo -CERC- 75a Vit Prepared for Headquarters, U.S. Army Corps of Engineers The contents of this report are not to be used for advertising, publication, or promotional purposes. Citation of trade names does not constitute an official endorsement or approval of the use of such commercial products. 7 GS PRINTED ON RECYCLED PAPER DEMCO Technical Report CERC-93-9 June 1993 Annual Data Summary for 1991 CERC Field Research Facility Volume I: Main Text and Appendixes A and B by Michael W. Leffler, Clifford F. Baron, Brian L. Scarborough, Kent R. Hathaway Coastal Engineering Research Center U.S. Army Corps of Engineers Waterways Experiment Station 3909 Halls Ferry Road Vicksburg, MS 39180-6199 I MBL/WHOI wh 0 0301 0091347 1 A Final report Approved for public release; distribution is unlimited Prepared for U.S. Army Corps of Engineers Washington, DC 20314-1000 Under FRF Analysis Work Unit 32525 US Army Corps of Engineers Waterways Experiment Station oN aA il 1 Hy . . FOR INFORMATION CONTACT ENVIRONMENTAL | PIA [54s ie y PUBLIC AFFAIRS OFFICE LABORATORY Cy (<9) 2 Wet) ‘ U. S. ARMY ENGINEER x — / WATERWAYS EXPERIMENT STATION 3909 HALLS FERRY ROAD VICKSBURG, MISSISSIPPI 39180-6199 PHONE : (601)634-2502 . cab m/f =p (es {soon i oa AREA OF RESERVATION = 2.7 sq km Waterways Experiment Station Cataloging-in-Publication Data Annual data summary for 1991 CERC Field Research Facility / by Michael W. Leffler ... [et al.], Coastal Engineering Research Center ; prepared for Department of the Army, U.S. Army Corps of Engineers. 2 v. : ill. ; 28 cm. — (Technical report; CERC-93-9) 1. Ocean waves — North Carolina — Statistics. 2. Meteorology, Maritime — North Carolina — Statistics. 3. Oceanographic research stations — North Carolina — Duck. 4. Oceanography — North Caro- lina — Observations. |. Leffler, Michael W. II. United States. Army. Corps of Engineers. III. Coastal Engineering Research Center (U.S.) IV. U.S. Army Engineer Waterways Experiment Station. V. Series: Technical report (U.S. Army Engineer Waterways Experiment Station) ; CERC-93-9. TA7 W34no.CERC-93-9 PREFACE This report is the 13th in a series of annual data summaries authorized by Headquarters, US Army Corps of Engineers (HQUSACE), under Civil Works Research Work Unit 32525, "Field Research Facility Analysis," Coastal Flooding Program. Funds were provided through the US Army Engineer Waterways Experiment Station (WES), Coastal Engineering Research Center (CERC), under the program management of Ms. Carolyn M. Holmes, CERC. The HQUSACE Technical Monitors were Messrs. John H. Lockhart, Jr.; Barry W. Holliday; John G. Housley; and David A. Roellig. Data for the report were collected and analyzed at the WES/CERC Field Research Facility (FRF) in Duck, NC. The report was prepared by Mr. Michael W. Leffler, FRF, under the direct supervision of Mr. William A. Birkemeier, Chief, FRF Group, Engineering Development Division (EDD), and Mr. Thomas W. Richardson, Chief, EDD; and under the general supervision of Dr. James R. Houston and Mr. Charles C. Calhoun, Jr., Director and Assistant Director, CERC, respectively. Mr. Kent K. Hathaway, FRF, assisted with instrumentation, and Mr. Brian L. Scarborough, FRF, assisted with data collection. Messrs. Clifford F. Baron, Stephen T. Blanchard, Matthew E. Cahur, Jonathan J. Lee, and Mohsen Alhaddad, and Mses. Judy H. Roughton and Juliana Atmadja assisted with data analysis at the FRF. The National Oceanic and Atmospheric Administration/National Ocean Service maintained the tide gage and provided statistics for summarization. At the time of publication of this report, Director of WES was Dr. Robert W. Whalin. Commander was COL Leonard G. Hassell, EN. CONTENTS PREFACE PART PART PART PART PART PART PART PART PART I: INTRODUCTION Background d Organization of Repoee: Availability of Data II: METEOROLOGY . Air Temperature Atmospheric Pressure Precipitation . Wind Speed and Direction III: WAVES Measurement Instruments Digital Data Analysis and Sommerctimarion : Results IV: CURRENTS Observations Results V: TIDES AND WATER LEVELS Measurement Instrument Results VI: WATER CHARACTERISTICS Temperature Visibility Density . VII: SURVEYS VIII: PHOTOGRAPHY . Aerial Photographs Beach Photographs IX: STORMS 7-9 January 1991 11-12 January 1991 23 February 1991 6-7 March 1991 29 March 1991 . 20-21 April 1991 18-19 May 1991 23 June 1991 18-19 August 1991 —"Hurricane Bob" 25 August 1991 .. 1-2 September 1991 20 September 1991 3 October 1991 .. 16-17 October 1991 .. 28 October — 1 November 1991. 8-10 November 1991 19 December 1991 31 December 1991 REFERENCES APPENDIX A: SURVEY DATA . APPENDIX B: WAVE DATA FOR GAGE 630 . Daily H,, and T, Joint Diseribactons of Hoe and T, Cumulative Distributions of Wave Height . Peak Spectral Wave Period Distributions Persistence of Wave Heights Spectra . APPENDIX C*: WAVE DATA FOR GAGE 111 Daily H,, and T, Joint Distributions of A, and T, Cumulative Distributions of Wave Height . Peak Spectral Wave Period Distributions . Persistence of Wave Heights Spectra . APPENDIX D: WAVE DATA FOR GAGE 625 . Daily H,, and T, Joint Distributions of Hoe cial It, Cumulative Distributions of Wave Height . Peak Spectral Wave Period Distributions Persistence of Wave Heights Spectra . A limited number of copies of Appendixes C—E (Volume II) were published under separate cover. Copies are available from National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161. 3 APPENDIX E: WAVE DATA FOR GAGE 645 Daily Hi, and 1, - : - ba ios ua Joint Distributions of foe and T, Cumulative Distributions of Wave Height Peak Spectral Wave Period Distributions Persistence of Wave Heights Spectra . El El El El El E2 E2 ANNUAL DATA SUMMARY FOR 1991 CERG FIELD RESEARCH FACILITY PART I: INTRODUCTION Background 1. The US Army Engineer Waterways Experiment Station (WES), Coastal Engineering Research Center's (CERC'’s) Field Research Facility (FRF), located on 0.7 km? at Duck, NC (Figure 1), consists of a 561-m-long research pier and accompanying office and field support buildings. The FRF is located near the middle of Currituck Spit along a 100-km unbroken stretch of shoreline extend— ing south of Rudee Inlet, VA, to Oregon Inlet, NC. The FRF is bordered by the Atlantic Ocean to the east and Currituck Sound to the west. The facility is designed to (a) provide a rigid platform from which waves, currents, water levels, and bottom elevations can be measured, especially during severe storms; (b) provide CERC with field experience and data to complement labora— tory and analytical studies and numerical models; (c) provide a manned field facility for testing new instrumentation; and (d) serve as a permanent field base of operations for physical and biological studies of the site and adjacent region. 2. The research pier is a reinforced concrete structure supported on 0.9-m-diam steel piles spaced 12.2 m apart along the pier’s length and 4.6 m apart across the width. The piles are embedded approximately 20 m below the ocean bottom. The pier deck is 6.1 m wide and extends from behind the dune- line to about the 6-m water depth contour at a height of 7.8 m above the National Geodetic Vertical Datum (NGVD). The pilings are protected against sand abrasion by concrete erosion collars and against corrosion by a cathodic system. 3. An FRF Measurements and Analysis Program has been established to collect basic oceanographic and meteorological data at the site, reduce and analyze these data, and publish the results. 4. This report, which summarizes data for 1991, continues a series of reports begun in 1977. ee CY IIS | 3 oe SP ine ay Research Facility Figure 1. FRF location map Organization of Report 5. This report is organized into nine parts and five appendixes. Part I is an introduction; Parts II through VIII discuss the various data col- lected during the year; and Part IX describes the storms that occurred. Appendix A presents the bathymetric surveys, Appendix B summarizes deepwater wave statistics, and Appendixes C through E (published under separate cover as Volume II) contain summary statistics for other gages. 6. In each part of this report, the respective instruments used for monitoring the meteorological or oceanographic conditions are briefly described, along with data collection and analysis procedures and data results. The instruments were interfaced with the primary data acquisition system, a Digital Equipment Corporation (Maynard, MA) VAX-11/750 minicomputer located in the FRF laboratory building. More detailed explanations of the design and the operation of the instruments may be found in Miller (1980). Readers’ comments on the format and usefulness of the data presented are encouraged. Availability of Data 7. Table 1 summarizes the available data. In addition to the wave data summaries in the main text, more extensive summaries for each of the wave gages are provided in Appendixes B through E. Table 1 1991 Data Availability Gage Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec M 1234512341234123451234123412345123412341234512341234 Weather Anemometer 932 ¥ kek RK RR we eR ee ee we ek Hee feo oe ae ok reek a ek ek ok ok ok ek ok oe ee Atmospheric Pres. 616 HAKKAR RR RR RR J ko RR RR R/O Ok Air Temperature 624 * Ke KKK KKK KKK KK RRR fk a ee ee Oe Ke Precipitation 604 * * Kw we ee ef ee re erie Jie ae re itt eee eee ee ee Waves Offshore Waverider 630 * / / ------ [RRKKKKK KKK KKK kK KKKK KARA RRA RA RK Rf - - Pressure Gage OO ey a i Pier End 625 * ke RK RRR fe RK ee Re ee me fk we we wm re ode te ore ote owe oe te te te rere tere ee ek ke ee Pier Nearshore 645 *¥ KK RK KKK KK KR ee eR ee we / oe wo er ok we rk wk oe ke oe oe ke oe eo oe ee Ok Currents Pier End ny A A ed Pier Nearshore www ff & fe Re ee Re ee we oe re oe re ee ie re ei ie ie oie ae ke ete eee ee tek J ek re eke oe oe ee Beach LILES LLL LRH * * [RK LLL Lee K LL fl fl -///*/* Pier End Tide Gage KKK KK RK ROR KR RK KR RK KR RK KR KR KK KR wR KR RK kw ee KR KK TR KR KR e/a Water Characteristics Temperature i ee i a a eg Visibility ed Ref fee eae KK AK Ke ee Density kak AK aR KKK KKK KA KK RR ee roe oe tk eo ow ie / ----- [Raw we Bathymetric Surveys * * * * * * * * ko * Photography Beach LF DF PTI LILI EPL LG CHD EP II PRI EP LPR EI ETE oS EPCOT ERG LT LPR TF CT RPP ERE EH ED ee OS Led ee oP // 0 Aerial Notes: * Full week of data obtained. / Less than 7 days of data obtained. - No data obtained. 8. The annual data summary herein summarizes daily observations by month and year to provide basic data for analysis by users. Daily measure- ments and observations have already been reported in a series of monthly Preliminary Data Summaries (FRF 1991). If individual data for the present year are needed, the user can obtain detailed information (as well as the monthly and previous annual reports) from the following address: USAE Waterways Experiment Station Coastal Engineering Research Center Field Research Facility 1261 Duck Rd. Kitty Hawk, NC 27949-4472 Although the data collected at the FRF are designed primarily to support ongoing CERC research, use of the data by others is encouraged. Tidal data other than the summaries in this report can be obtained directly from the following address: National Oceanic and Atmospheric Administration National Ocean Service ATTN: Tide Analysis Branch Rockville, MD 20852 A complete explanation of the exact data desired for specific dates and times will expedite filling any request; an explanation of how the data will be used will help CEIAC or the National Oceanic and Atmospheric Administration (NOAA) /National Ocean Service (NOS) determine whether other relevant data are available. For information regarding the availability of data for all years, contact the FRF at 919-261-3511. Costs for collecting, copying, and mailing will be borne by the requester. PART II: METEOROLOGY 9. This section summarizes the meteorological measurements made during the current year and in combination with all previous years. Meteorological measurements during storms are given in Part IX. 10. Mean air temperature, atmospheric pressure, and wind speed and direction were computed for each data file, which consisted of data sampled two times per second for 34 min every 6 hr beginning at or about 0100, 0700, 1300, and 1900 hr eastern standard time (EST); these hours correspond to the time that the National Weather Service (NWS) creates daily synoptic weather maps. During storms, data recordings were made more frequently. Meteorological data are summarized in Table 2. Table 2 Meteorological Statistics Mean Mean Wind Resultants Air Temperature Atmospheric Pres. Precipitation, mm 1991 1980-1991 deg C mb 1991 1978-1991 Speed Direction Speed Direction Month 1991 1983-1991 1991 1983-1991 Total Mean Maxima Minima m/sec deg m/sec deg Jan 7.3 5.9 1018.2 1017.9 142 101 180 44 2.6 341 2.3 333 Feb 7.8 6.8 1015.5 1017.5 8 72 113 20 2.0 306 1.7 342 Mar 11.2 7 1009.4 1016.2 186 100 206 35 2.0 268 1.4 355 Apr 15.0 13.7 1015.4 1013.8 73 97 182 0 0.3 322 0.3 328 May 22.6 19.2 1015.9 1015.8 7 72 239 20 7 156 0.6 187 Jun 26.8 23.8 1013.9 1015.3 59 86 136 27 0.6 92 1.0 198 Jul 29.4 26.4 1012.9 1016.0 150 99 275 19 2.4 217 1.8 210 Aug 26.1 25.9 1014.8 1016.0 114 98 221 30 0.6 159 0.5 97 Sep 25.7 22.8 1017.6 1017.6 7 77 226 5 2.1 63 2.0 40 Oct 21.5 18.2 1016.8 1019.1 124 70 143 17 2.6 15 2.3 26 Nov 16.8 13.6 1018.4 1018.3 46 87 145 26 1.7 321 1.7 344 Dec 9.8 8.1 1019.2 1019.5 97 66 131 4 2.4 294 2.1 328 Average 18.3 16.2 1015.7 1016.9 84 85 7 318 0.8 351 Total 1013. 1025 Air Temperature 11. The FRF enjoys a typical marine climate that moderates the temper- ature extremes of both summer and winter. Measurement instruments 12. A Yellow Springs Instrument Company, Inc. (YSI) (Yellow Springs, OH) electronic temperature probe with analog output interfaced to the FRF’s computer was operated beside the NWS’s meteorological instrument shelter located 43 m behind the dune (Figure 2). To ensure proper temperature 9 Pressure Gage No. 111 0.9 km offshore BaylorGage BaylorGage a nemometer No. C7 No. 625 Tide Gage > No. 865-1370 Waverider Buoy No. 630 6 km offshore Figure 2. FRF gage locations 10 readings, the probe was installed 3 m above ground inside a "coolie hat" to shade it from direct sun, yet provide proper ventilation. Results 13. Daily and average air temperature values are tabulated in Table 2 and shown in Figure 3. Atmospheric Pressure Measurement instruments 14. Electronic atmospheric pressure sensor. Atmospheric pressure was measured with a YSI electronic sensor with analog output located in the laboratory building at 9 m above NGVD. Data were recorded on the FRF com- puter. Data from this gage were compared with those from an NWS aneroid barometer to ensure proper operation. 15. Microbarograph. A Weathertronics, Incorporated (Sacramento, CA) recording aneroid sensor (microbarograph) located in the laboratory building also was used to continuously record atmospheric pressure variation. 16. The microbarograph was compared daily with the NWS aneroid barometer, and adjustments were made as necessary. Maintenance of the microbarograph consisted of inking the pen, changing the chart paper, and winding the clock every 7 days. During the summer, a meteorologist from the NWS checked and verified the operation of the barometer. 17. The microbarograph was read and inspected daily using the following procedure: a. The pen was zeroed (where applicable). b. The chart time was checked and corrected, if necessary. c. The daily reading was marked on the chart for reference. d. The starting and ending chart times were recorded, as necessary. e. New charts were installed, when needed. 11 fo) 35 } Een Year Mean, C *—x 1991 18.3 +. @----© 1983-91 16.2 30 25 20 15 10 Air Temperature, e JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 3. Daily air temperature values with monthly means Results 18. Daily and average atmospheric pressure values are presented in Figure 4, and summary statistics are presented in Table 2. Precipitation 19. Precipitation is generally well distributed throughout the year. Precipitation from mid-latitude cyclones (northeasters) predominates in the winter, whereas local convection (thunderstorms) accounts for most of the summer rainfall. Measurement instruments 20. Electronic rain gage. A Belfort Instrument Company (Baltimore, MD) 30-cm weighing rain gage, located near the instrument shelter 47 m behind the dune, measured daily precipitation. According to the manufacturer, the instrument's accuracy was 0.5 percent for precipitation amounts less than 12 1040 Year Mean, mb - x—x 1991 1015.7 3 @----0 1983-91 1015.9 Atmospheric Pressure, mb JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 4. Daily barometric pressure values with monthly means 15 cm and 1.0 percent for amounts greater than 15 cm. 21. The rain gage was inspected daily, and the analog chart recorder was maintained by procedures similar to those for the microbarograph. 22. Plastic rain gage. An Edwards Manufacturing Company (Alberta Lea, MN) True Check 15-cm-capacity clear plastic rain gage with a 0.025-cm resolu- tion was used to monitor the performance of the weighing rain gage. This gage was located near the weighing gage, and the gages were compared on a daily basis. Very few discrepancies were identified during the year. Results 23. Daily and monthly average precipitation values are shown in Figure 5. Statistics of total precipitation for each month during this year and average totals for all years combined are presented in Table 2. 13 Year Total, mm x—x 1991 1013 @----© 1978-91 1025 Precipitation, mm : ° ce eee cee JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 5. Daily precipitation values with monthly totals Wind Speed and Direction 24. Winds at the FRF are dominated by tropical maritime air masses that create low to moderate, warm southern breezes; arctic and polar air masses that produce cold winds from northerly directions; and smaller scale cyclonic, low pressure systems, which originate either in the tropics (and move north along the coast) or on land (and move eastward offshore). The dominant wind direction changes with the season, being generally from northern directions in the fall and winter and from southern directions in the spring and summer. It is common for fall and winter storms (northeasters) to produce winds with average speeds in excess of 15 m/sec. Measurement instrument 25. Winds were measured at the seaward end of the pier at an elevation of 19.1 m (Figure 2) using a Weather Measure Corporation (Sacramento, CA) Skyvane Model W102P anemometer. Wind speed and direction data were collected on the FRF computer. The anemometer manufacturer specifies an accuracy of +0.45 m/sec below 13 m/sec and 3 percent at speeds above 13 m/sec, with a 14 threshold of 0.9 m/sec. Wind direction accuracy is +2 deg, with a resolution of less than 1 deg. The anemometer is calibrated annually at the National Bureau of Standards in Gaithersburg, MD, and is within the manufacturer's specifications. Results 26. Annual and monthly joint probability distributions of wind speed versus direction were computed. Wind speeds were resolved into 3-m/sec intervals, whereas the directions were at 22.5-deg intervals (i.e., 16-point compass direction specifications). These distributions are presented as wind "roses," such that the length of the petal represents the frequency of occur- rence of wind blowing from the specified direction, and the width of the petal is indicative of the speed. Resultant directions and speeds were also deter- mined by vector-averaging the data (see Table 2). Wind statistics are pre- sented in Figures 6, 7, and 8. 15 N 337.50.0 995 315.0 45.0 67.5 25 aan as 6) W os i 90.0E 270.0 = ae a We " wag 112.5 202.5 180.0 ”"> Ss 1991 Speed 0.7 m/s Direction 318 deg N SEO sa6 315.0 45.0 292.5 a4 y - ee &® Ss» W a 90.0E 270.0 = = Q ay 247. ee / uv 112.5 i 135.0 202.5 180.0 >"> Ss 1980-1991 Speed 0.8 m/s Direction 351 deg 0 10 20 30 40 Frequency, % Figure 6. Annual wind roses 16 N N 337.50.0 995 337.50.0 995 315.0 45.0 315.0 | y 45.0 292.5 AS Ws ou: ey | bs S78 A ,," % Ww ee : 90.0F Wooo . 90:0E x, é jy vw 112.5 ee, / - 112.5 pote 135.0 an 135.0 202.5 180.07" 202.5 180.07" S Ss JANUARY FEBRUARY Speed 2.6 m/s Speed 2.0 m/s Direction 341 deg Direction 306 deg N N 337.50.0 995 337.50.0 995 315.0 45.0 315.0 45.0 292.5 onl i of2 292.5 aot y A o%° W 570.0 © E W570.0 i 90.0E 247. 7 ~ 112.5 247. cS i ~ 112.5 225 Af 135.0 225.0 135.0 202.5 180. give 202.5 180.0"> Ss MARCH APRIL Speed 2.0 m/s Speed 0.3 m/s Direction 268 deg Direction 322 deg 0 10 20 30 40 Frequency, % Monthly wind roses for 1991 (Sheet 1 of 3) Figure 7. 17 N N 337.50.0 995 337.50.0 995 315.0 45.0 315.0 45.0 67.5 67.5 292.5 a is 3 WW : -_ ® 7 ee Si) L\ 112.5 Ld " \* 112.5 225.0 135.0 225.0 135.0 202.5 180.0 °7-> 202.5 180.0 °7:> Ss Ss MAY JUNE Speed 1.2 m/s Speed 0.6 m/s Direction 156 deg Direction 92 deg N N 337.50.0 995 337.50.0 995 315.0 45.0 315.0 45.0 67.5 67.5 292.5 ode, 292.5 regs W : 90.0E W a 0.0E 270.0 — cae : 270.0 = a oe 112.5 —, S a i ae \ 1 a / z\ 112.5 135.0 225.0 135.0 202.5 180.0 7° 202.5 180.0 97> Ss S JULY AUGUST Speed 2.4 m/s Speed 0.6 m/s Direction 217 deg Direction 159 deg Speed, m/s N © 0O a GT Th ee LeneQ2mee28 OM omezo 40 Frequency, % Figure 7. 18 (Sheet 2 of 3) N 0.0 99.5 315.0 292.5 | 17 sie e > el] WwW zi 90.0E o 270.0 i 247.5 77, ha 225.0 202.5 180.0 S SEPTEMBER Speed 2.1 m/s Direction 63 deg 112.5 135.0 157.5 N 337.50.0 995 315.0 45.0 292.5 \s i, e7? Qe es W 90.0E 270.0 C= on @ 247.5 A py £0 f 202.5 180.0 !97-5 S 135.0 NOVEMBER Speed 1.7 m/s Direction 321 deg 0 10 Frequency, % Figure 7. ng N 337.50.0 995 315.0 45.0 292.5 Rt y ap oi 270.0 x 247.5 7 fie ys 225.0 202.5 180.0 ©7:> S W oO 135.0 OCTOBER Speed 2.6 m/s Direction 15 deg N 337.50.0 995 315.0 45.0 292.5 | oc2 nly W 90.0E dl a 270.0 = 202.5 180.0 97:5 S 112.5 DECEMBER Speed 2.4 m/s Direction 294 deg (Sheet 3 of 3) N N 337.5 0.0 22.5 337.5 0.0 22.5 315.0 45.0 315.0 q 45.0 292.5 aM f, Mes 292.5 cot I, S02 W cae: didi a 90,064 MiWora.o © 90.0E 47 ce, / " oe 112.5 247.5 a, / ay 112.5 225.0 135.0 225.0 135.0 202.5 180.0 ©”"> 202.5 180.0 7° JANUARY : se RUM. Speed 2.3 m/s Direction 333 deg Speed 1.7 m/s Direction 342 deg N N 557/5)0:0) m5) a 337.50.0 995 315.0 oan 315.0 45.0 292.5 a Py ee 292.5 a 7 4s ee Wesrae - 3 G0.0IE4 a aM coan 2 90.0E 247.5 ee a iv 112.5 247. ee “/ r 112.5 202.5 180.0 7° 202.5 180.0 ©7-> S S MARCH APRIL Speed 1.4 m/s Speed 0.3 m/s Direction 355 deg Direction 328 deg 0 10 20 30 40 Frequency, % Figure 8. Monthly wind roses for 1980 through 1991 (Sheet 1 of 3) 20 N N 337.5 0.0 22.5 337.5 0.0 22.5 315.0 45.0 315.0 45.0 2925 7 P4 eee 2025 iW F4 the Ae D> &® > Vad W 270.0 ie col 90.0E W 270.0 = col 90.0E Ea ey iw 112.5 WA / ine 112.5 225. 4 Teed 225.0 Ieee 202.5 180.0 97> 202.5 180.0 7° S Ss MAY JUNE Speed 0.6 m/s Speed 1.0 m/s Direction 187 deg Direction 198 deg N N 337.5 0.0 22.5 337.5 0.0 22.5 315.0 45.0 315.0 45.0 292.5 anya, I eas 292.5 rh 7 Zz 2 D> W ey as 90.0E W 90.0E ie 0 = 7 270. = = eS = 112.5 112.5 ory uvy oS fur SG 135.0 poate 135.0 202.5 180.0 °7-> 202.5 180.0"7"> S Ss JULY AUGUST Speed 1.8 m/s Speed 0.5 m/s Direction 210 deg Direction 97 deg Speed, m/s Ne ee beer npr ae elie das Sees ONION ZONE SONE40 Frequency, % Figure 8. (Sheet 2 of 3) 21 N 337.50.0 995 Direction 344 deg N 337.50.0 995 315.0 f 45.0 315.0 292.5 al ts; St? 292.5 ani is a oh 90.0E W 90.0 270.0 ae ; 270.0 2 247 SS vy 112.5 247.5 i, . 112.5 i l 0 O O fl L Wy i ORG 135.0 225.0 135.0 202.5 180.0 97:5 202.5 180.0 7° Ss Ss SEPTEMBER OCTOBER Speed 2.0 m/s Speed 2.3 m/s Direction 40 deg Direction 26 deg N N 337.50.0 995 337.50.0 99. my 315.0 45.0 315.0 67.5 292.5 { fe 292.5 |. hf s soln, 270.0 = le 90.0F W700 b 2 90.0E 247.5 / ‘hed 112.5 ey " od 112.5 SAG 135.0 Dong 135.0 202.5 180.0 97-9 202.5 180.0 79 S S NOVEMBER DECEMBER Speed 1.7 m/s Speed 2.1 m/s Direction 328 deg 0 10 20 30 40 Frequency, % Figure 8. (Sheet 3” of 13) 22 PART III: WAVES 27. This section presents summaries of the wave data. A discussion of individual major storms is given in Part IX and contains additional wave data for times when wave heights exceeded 2 m at the seaward end of the FRF pier. Appendixes B through E provide more extensive data summaries for each gage, including height and period distributions, wave direction distributions, persistence tables, and spectra during storms. 28. Wave directions (similar to wind directions) at the FRF are season- ally distributed. Waves approach most frequently from north of the pier in the fall and winter and south of the pier in the summer, with the exception of storm waves that approach twice as frequently from north of the pier. Annually, waves are approximately evenly distributed between north and south (resultant wave direction being almost shore-normal). Measurement Instruments 29. The wave gages included two wave staff gages (Gages 645 and 625), one buoy gage (Gage 630), and one pressure gage (Gage 111) as shown in Figure 2 and located as follows: Distance Offshore Water Depth Operational Gage Type/Number from Baseline m Period Continuous wire (645) 238 m 3.5 11/84-12/91 Continuous wire (625) 567 m 8 11/78-12/91 Accelerometer buoy (630) 6 km 18 11/78-12/91 Pressure gage (111) 1 km 9 09/86-12/91 Staff gages 30. Two Baylor Company (Houston, TX) parallel cable inductance wave gages (Gage 645 at sta 7+80 and Gage 625 at sta 19+00 (Figure 2)) were mounted on the FRF pier. Rugged and reliable, these gages require little maintenance except to keep tension on the cables and to remove any material that may cause an electrical short between them. They were calibrated prior to installation by creating an electrical short between the two cables at known distances along the cable and recording the voltage output. Electronic signal conditioning amplifiers are used to ensure that the output signals from the gages are within a O- to 5-V range. Manufacturer—stated gage accuracy is about 1.0 percent, with a 0.1—percent full-scale resolution; full scale is 14 m for Gage 625 and 8.2 m for Gage 645. These gages are susceptible to 23 lightning damage, but protective measures have been taken to minimize such occurrences. A more complete description of the gages’ operational charac— teristics is given by Grogg (1986). Buo age 31. One Datawell Laboratory for Instrumentation (Haarlem, The Nether-— lands) Waverider buoy gage (Gage 630) measures the vertical acceleration pro— duced by the passage of a wave. The acceleration signal is double—integrated to produce a displacement signal transmitted by radio to an onshore receiver. The manufacturer stated that wave amplitudes are correct to within 3 percent of their actual value for wave frequencies between 0.065 and 0.500 Hz (corresponding to 15- to 2—sec wave periods). The manufacturer also specified that the error gradually increased to 10 percent for wave periods in excess of 20 sec. The results in this report were not corrected for the manufacturer's specified amplitude errors. However, the buoy was calibrated semiannually to ensure that it was within the manufacturer’s specification. Pressure gage 32. One Senso—Metrics, Incorporated (Simi Valley, CA), pressure trans— duction gage (Gage 111) installed near the ocean bottom measures the pressure changes produced by the passage of waves creating an output signal that is linear and proportional to pressure when operated within its design limits. Predeployment and postdeployment precision calibrations are performed at the FRF using a static deadweight tester. The sensor's range is 0 to 25 psi (equivalent to 0- to 17-m seawater) above atmospheric pressure with a manufac— turer-stated accuracy of +0.25 percent. Copper scouring pads are installed at the sensor’s diaphragm to reduce biological fouling, and the system is periodically cleaned by divers. Digital Data Analysis and Summarization 33. The data were collected, analyzed, and stored on magnetic tape using the FRF’s VAX computer. Data sets were normally collected every 6 hr. During storms, the collection was at 3-hr intervals. For each gage, a data set consisted of four contiguous records of 4,096 points recorded at 0.5 Hz (approximately 34 min long), for a total of 2 hr and 16 min. Analysis was performed on individual 34-min records. 34. The analysis program computes the first moment (mean) and the 24 second moment about the mean (variance) and then edits the data by checking for "jumps," "spikes," and points exceeding the voltage limit of the gage. A jump is defined as a data value greater than five standard deviations from the previous data value, whereas a spike is a data value more than five standard deviations from the mean. If less than five consecutive jumps or spikes are found, the program linearly interpolates between acceptable data and replaces the erroneous data values. The editing stops if the program finds more than five consecutive jumps or spikes, or more than a total of 100 bad points, or the variance of the voltage is below 1 x 10° squared volts. The statistics and diagnostics from the analysis are saved. 35. Sea surface energy spectra are computed from the edited time series. Spectral estimates are computed from smaller data segments obtained by dividing the 4,096—point record into several 512—point segments. The estimates are then ensemble—averaged to produce a more accurate spectrum. These data segments are overlapped by 50 percent (known as the Welch (1967) method) which has been shown to produce better statistical properties than nonoverlapped segments. The mean and linear trends are removed from each segment prior to spectral analysis. To reduce side—lobe leakage in the spec— tral estimates, a data window was applied. The first and last 10 percent of data points were multiplied by a cosine bell (Bingham, Godfrey, and Tukey 1967). Spectra were computed from each segment with a discrete Fast Fourier Transform and then ensemble—-averaged. Sea surface spectra from subsurface pressure gages were obtained by applying the linear wave theory transfer function. 36. Unless otherwise stated, wave height in this report refers to the energy—based parameter H,, defined as four times the zeroth moment wave height of the estimated sea surface spectrum (i.e., four times the square root of the variance) computed from the spectrum passband. Energy computations from the spectra are limited to a passband between 0.05 and 0.50 Hz for sur- face gages and between 0.05 Hz and a high-frequency cutoff for subsurface gages. This high-frequency limit is imposed to eliminate aliased energy and noise measurements from biasing the computation of H,, and is defined as the frequency where the linear theory transfer function is less than 0.1 (spectral values are multiplied by 100 or more). Smoother and more statistically significant spectral estimates are obtained by band—averaging contiguous spectral components (three components are averaged per band, producing a 25 frequency band width of 0.0117 Hz). 37. Wave period T, is defined as the period associated with the maximum energy band in the spectrum, which is computed using a 3-point running average band on the spectrum. The peak period is reported as the reciprocal Ob themcentersirequenciys | Gilmer wall uae 1/frequency) of the spectral band with the highest energy. A detailed description of the analysis techniques is presented in a report by Andrews (1987) .* Results 38. The wave conditions for the year are shown in Figure 9. For all four gages, the distributions of wave height for the current year and all years combined are presented in Figures 10 and 11, respectively. Distribu- tions of wave period are presented in Figure 12. 39. Multiple-year comparisons of data for Gage 111 actually incorporate data for 1985 and 1986 from Gage 640 (a discontinued Waverider buoy previously located at the approximate depth and distance offshore of Gage 111) and data for 1987 from Gage 141, located 30 m south of Gage 111. 4O. Refraction, bottom friction, and wave breaking contribute to the observed differences in height and period. During the most severe storms when the wave heights exceed 3 m at the seaward end of the pier, the surf zone (wave breaking) has been observed to extend past the end of the pier and occasionally 1 km offshore. This occurrence is a major reason for the dif- ferences in the distributions between Gage 630 and the inshore gages. The wave height statistics for the staff gage (Gage 645), located at the landward end of the pier, were considerably lower than those for the other gages. In all but the calmest conditions, this gage is within the breaker zone. Con- sequently, these statistics represent a lower energy wave climate. 41. Summary wave statistics for the current year and all years combined are presented for Gage 630 in Table 3. * M. E. Andrews. 1987. "Standard Wave Data Anfresis Procedures for Coastal Engineering Applications," unpublished report prepared for the US Army Engineer Waterways Experiment Station, Vicksburg, MS. 26 Height, m ON FOND FON FON FOND F&F OH & 13.5 7 9 1113 15 17 19 2123252729 1 3 5 7 9 1113 15 17 19 2123 25 27 29 31 Day of the Month Period, sec a No = N oO oo oO oo oO 20 13 5 7 9 111315 1719 2123252729 1 3 5 7 9 111315 17 19 212325 27 29 31 Day of the Month Figure 9. 1991 time histories of wave height and period for Gage 630 27 Height, m Height, m (0) 10m 10m 10° 10 10 Percent Greater Than Indicated Figure 10. 1991 annual wave height distributions 0 Ona On 10° 10) 10 Percent Greater Than Indicated Figure 11. Annual distribution of wave heights for 1980 through 1991 28 Gage 630 1991 Gage 630 1980-91 =z he Va — ial __ AGA _| ood ne : Gage 111 1991 Gage 111 1985-91 : 7 y VPA W A = ee __ naan. 3 Gage 625 1991 Gage 625 1980-91 & PAP _ aia __ aaah no} onaeaan Gage 645 Gage 645 6 8 1 Period, sec Period, sec Figure 12. Annual wave period distributions for all gages 29 Table 3 Wave Statistics for Gage 630 1991 1980-1991 Height Period Height Period Std. Std. Std. Std. Mean Dev. Extreme Mean Dev. Number Mean Dev. Extreme Mean Dev. Number Month _m om __ mi _ Date _sec sec Obs. _m _m -_omi _ Date _sec _sec _Obs._ Jan ab 8) 0.7 3.2 9 8.0 a5) 61 1.2 0.7 4.5 1983 8.1 2.7 1255 Feb 1.4 0.7 2.8 23 Uo) 1.7 25 2 0.7 5},.ah 1987 8.4 2.6 1146 Mar TZ OPTS. 7.54 30 9.2 2.4 118 eA Wa 7/ 4.7 1983 8.7 2.6 1358 Apr 1.0 0.6 3.5 20 7.9 1.8 120 1.0 0.6 5.0 1988 8.6 2.6 1327 May 0.8 0.5 2.6 19 7.8 2.9 122 0.9 0.5 3.3 1986 8.1 2.5 1351 Jun 0.9 0.5 2.7 23 8.4 1.9 106 0.8 0.4 Aad 1991 7.8 2.2 1244 Jul 0.7 0.2 1.3 30 7.8 2.1 116 0.7 0.3 2.1 1985 8.1 2.4 1280 Aug 0.8 O.5 3.5 19 8.9 25) 123 0.8 O.5 3.6 1981 Ber 58) 1303 Sep shoal 0.5 2.6 1 8.1 1.7 119 1.1 0.6 6.1 1985 8.6 2.6 1310 Oct 1.4 1.0 5.4 ejal 9.7, 3.4 122 1.3 0.7 5.4 1991 8.8 2.8 1361 Nov Al, a 0.9 4.6 9 8.2 2.9 118 1.1 0.7 4.6 1991 7.9 2.8 1155 Dec 1.0 0.5 2i9) 19 7.5 2.6 41 1.2 0.8 5.6 1980 8.2 2.9 1108 Annual abel 0.6 5.4 Oct 8.3 2.6 1191 1.0 0.6 6.1 Sep 1985 8.3 2.6 15198 42. Annual joint distributions of wave height versus wave period for Gage 630 are presented for 1991 in Table 4, and for all years combined in Table 5. Similar distributions for the other gages are included in Appen— dixes B-E. 43. Annual distributions of wave directions (relative to true north) based on daily observations of direction at the seaward end of the pier and height from Gage 625 (or Gage 111 when data for Gage 625 were unavailable) are shown in Figure 13. Monthly wave "roses" for 1991 and all years combined are presented in Figures 14 and 15, respectively. 30 Table 4 Annual (1991) Joint Distribution of H,, versus T, for Gage 630* Pp Period, sec 20> 3.0 800 50= 60° 760 Bo9= D505 10,0° 150= UY.0- B60 Height, m 7A) 3.9 4.9 5),,0) 6.9 7/39) 8.9 929 11.9 _13.9 _15.9' _Longer Total 0.00 - 0.49 8 17 17 50 50 84 319 243 168 34 126 25 1141 02505 — 10299 17 118 285 596 655 579 982 840 974 101 218 0 5365 1.00 - 1.49 é 5 84 437 269 193 537 218 176 25 92 2031 ih) = aloe) 4 A 17 176 227 101 92 76 101 17 34 : 841 2.00 - 2.49 : 5 F 25 118 50 42 25 25 8 7 0 293 %5\)) = ASK) : 0 . : 50 50 34 é 3 8 17 0 159 3.00 - 3.49 8 25 8 8 17 8 8 82 5G) = &i.O8) o 8 8 8 6 24 4.00 - 4.49 é 8 8 8 8 32 4.50 - 4.99 8 8 16 5.00 - Greater 5 4 3 : 6 4 3 6 0 8 8 Total 25 135 403 1284 1377 1082 2022 1426 1460 218 503 57 * Percent occurrence (x100) of height and period. Table 5 Annual (1980-1991) Joint Distribution of H,, versus T, for Gage 630 (All Years)* Period, sec AW? Si- 4o0° 3.0 G.0- 7oe B.0e Yo LOO 1Bo0e IA, W6.0- Height, m 2.9 é\0) 4.9 a8) 6.9 Uae) 8.9 9.9 11.9 _13.9 _15.9 _Longer Total 0.00 - 0.49 27 14 26 60 86 114 332 278 189 66 126 5 1323 0.50 - 0.99 37 136 255 509 592 526 882 744 801 140 229 16 4867 1.00 - 1.49 9. 143 405 424 251 284 212 322 40 121 3 2214 1D Oe. 99, 13 164 245 111 83 78 126 32 72 4 928 2.00 - 2.49 1 24 95 67 54 37 59 27 36 1 401 Ze50e— ee 99 1 12 32 18 13 32 10 24 a 143 3.00 - 3.49 F 1 12 12 12 14 5 8 a, 65 3.50 - 3.99 5 1 6 7 ilal 4 5 34 4.00 - 4.49 : 2 4 7 1 3 1 18 4.50 - 4.99 f é 6 0 . 6 fs 1 2 6 : 1 4 5.00 - Greater 6 , 4 . : 6 al A 1 al 1 1 5 Total 64 159 438 1163 1455 1114 1674 1386 1564 326 625 34 * Percent occurrence (x100) of height and period. 31 1991 Height 0.7 m Direction 65 deg N 0.0 99.5 45.0 ae if, 67.5 1980-91 Height 0.7 m Direction 66 deg Height, m SP Ome fom On) OS oO a N N) > oO Te) 0 20 40 60 80 100 Frequency, % Figure 13. Annual wave roses 32 N 0.0 99.5 45.0 "| P 67.5 = 90.0E ~S . 112.5 135.0 S JANUARY Height 0.8 m Direction 33 deg MARCH Height 0.7 m Direction 60 deg 0 Figure 14. Height, m On Ome = x] ) 20 40 60 Frequency, % 33 22.5 = 90.0E SS 112.5 S FEBRUARY Height 0.6 m Direction 27 deg APRIL Height 0.7 m Direction 68 deg o Oo ~ ow 80 100 Monthly wave roses for 1991 (Sheet 1 of 3) MAY Height 0.5 m Direction 87 deg JULY Height 0.4 m Direction 89 deg JUNE Height 0.7 m Direction 79 deg 45.0 67.5 ? se \ — 5) [5 Sy, 112.5 S AUGUST Height 0.6 m Direction 89 deg Height, m OU Oa Orne asec Oy US Neg iro 0 20 40 60 80 100 Frequency, % Figure 14. (Sheet 2 of 3) 34 SEPTEMBER Height 0.9 m Direction 78 deg lew NN 112.5 135.0 S NOVEMBER Height 0.7 m Direction 62 deg N 0.0 99.5 45.0 ivA 67.5 \- all 90.0E \ 112.5 135.0 S OCTOBER Height 1.0 m Direction 68 deg N 0.0 99.5 45.0 ; ly, 67.5 \ 7 = 90.0E > a° 112.5 135.0 157.5 S DECEMBER Height 0.7 m Direction 50 deg Height, m 2 One Le. 2S) aS So £2 SN &@ VY & 0 20 40 60 80 100 Frequency, % Figure 14. (Sheet 3 of 3) 35 JANUARY Height 0.8 m Direction 56 deg N 0.0 99.5 45.0 A y 67.5 “ 90.0E ay % 112.5 135.0 157.5 S MARCH Height 0.9 m Direction 63 deg 0 Figure 15. Height, m oO} pon ae - AN 20 FEBRUARY Height 0.9 m Direction 59 deg N 0.0 99.5 45.0 - Yi aa 67.5 ia 135.0 157.5 Ss APRIL Height 0.8 m Direction 67 deg 2° +r wo 40 60 80 100 Frequency, % Monthly wave roses for 1980 through 1991 (Sheet 1 of 3) 36 E MAY Height 0.6 m Direction 74 deg JULY Height 0.4 m Direction 82 deg 0 Figure 15. JUNE Height 0.5 m Direction 77 deg AUGUST Height 0.6 m Direction 76 deg SQ © wo (Sheet 2 of 3) N 22.5 0: CR2205 45.0 45.0 67.5 67.5 vA eS ce ~ 112.5 ‘ 112.5 135.0 135.0 S S SEPTEMBER OCTOBER Height 0.8 m Height 1.0 m Direction 71 deg Direction 67 deg N N 0.0 995 002215 45.0 45.0 “) 4 67.5 g 7 Us 67.5 = we 112.5 G 112.5 135.0 135.0 157.5 S S NOVEMBER DECEMBER Height 0.9 m Height 0.8 m Direction 61 deg Direction 58 deg Height, m Cp Sig wt wo a8 N m 20 40 60 80 100 0 Frequency, % Figure 15 (Sheet 3 of 3) 38 PART IV: CURRENTS 44. Surface current speed and direction at the FRF are influenced by winds, waves, and, indirectly, by the bottom topography. The extent of the respective influences varies daily. However, winds tend to dominate the cur— rents at the seaward end of the pier, whereas waves dominate within the surf zone. Observations 45. Near 0700 EST, daily observations of surface current speed and direction were made at (a) the seaward end of the pier, (b) the midsurf position on the pier, and (c) 10 to 15 m from the beach 500 m updrift of the pier. Surface currents were determined by observing the movement of dye on the water surface. Results 46. Annual mean and mean currents for 1980 through 1991 are presented in Table 6 and in Figure 16. Figure 16 shows the daily and average annual measurements at the beach, pier midsurf, and pier end locations. Since the relative influences of the winds and waves vary with position from shore, the current speeds and, to some extent, direction vary at the beach, midsurf, and pier end locations. Magnitudes generally are largest at the midsurf location and lowest at the end of the pier. 39 Table 6 Mean Longshore Surface Currents* Pier End, cm/sec Pier Midsurf, cm/sec Beach, cm/sec 1980- 1980- 1980- Month 1991 1991 1991 1991 1991 1991 Jan 30 22 20 18 ay 5 Feb -6 5 1 5 5 8 Mar 11 14 5 8 3 8 Apr 15 13 23 12 -2 2 May 28 19 15 5 10 4 Jun 17 11 14 3 16 5 Jul 0 2 2 -7 -4 -8 Aug 20 15 7 -2 1 = Sep 7 7 11 al -1 -2 Oct -5 1 -7 -4 -10 -5 Nov -3 5 ol 4 -4 4 Dec 11 13 9 13 -1 5 Annual 10 11 8 5 1 2 * + = southward; - = northward. 40 Current Speed, cm/s Pier End Year Mean, cm/s ——* 1991 10 @=---01980-91 11 Pier Midsurf Year Mean, cm/s —« 1991 8 @---0 1980-91 5 Beach (500 m Updrift) ,,., Mean, cm/s ——« 1991 1 @=---0 1980-91 2 Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Figure 16. Daily current speeds and directions with monthly means for 1991 41 PART V: TIDES AND WATER LEVELS Measurement Instrument 47. Water level data were obtained from an NOAA/NOS control tide station (sta 865-1370) located at the seaward end of the research pier (Figure 2) by using a Leupold and Stevens, Inc. (Beaverton, OR) digital tide gage. This analog-to-digital recorder is a float-activated, negator-spring, counterpoised instrument that mechanically converts the vertical motion of a float into a coded, punched paper tape record. The below-deck installation at pier sta 19+60 consisted of a 30.5-cm-diam stilling well with a 2.5-cm orifice and a 21.6-cm—diam float. 48. Operation and tending of the tide gage conformed to NOS standards. The gage was checked daily for proper operation of the punch mechanism and for accuracy of the time and water level information. The accuracy was determined by comparing the gage level reading with a level read from a reference elec— tric tape gage. Once a week, a heavy metal rod was lowered down the stilling well and through the orifice to ensure free flow of water into the well. During the summer months, when biological growth was most severe, divers inspected and cleaned the orifice opening as required. 49. The tide station was inspected quarterly by an NOAA/NOS tide field group. Tide gage elevation was checked using existing NOS control positions, and the equipment was checked and adjusted as needed. Both NOS and FRF personnel also reviewed procedures for tending the gage and handling the data. Any specific comments on the previous months of data were discussed to ensure data accuracy. 50. Digital paper tape records of tide heights taken every 6 min were analyzed by the Tides Analysis Branch of NOS. An interpreter created a digi- tal magnetic computer tape from the punch paper tape, which was then processed on a large computer. First, a listing of the instantaneous tidal height values was created for visual inspection. If errors were encountered, a com— puter program was used to fill in or recreate bad or missing data using cor- rect values from the nearest NOS tide station and accounting for known time lags and elevation anomalies. The data were plotted, and a new listing was generated and rechecked. When the validity of the data had been confirmed, monthly tabulations of daily highs and lows, hourly heights (instantaneous 42 height selected on the hour), and various extreme and/or mean water level statistics were computed. Results 51. Tides at the FRF are semidiurnal with both daily high and low tides approximately equal. Tide height statistics are presented in Table 7. Figure 17 plots the monthly tide statistics for all available data, and Figure 18 compares the distribution of daily high and low water levels and hourly tide heights. The monthly or annual mean sea level (MSL) reported is the average of the hourly heights, whereas the mean tide level is midway between mean high water (MHW) and mean low water (MLW), which are the averages of the daily high- and low-water levels, respectively, relative to NGVD. Mean range (MR) is the difference between MHW and MLW levels, and the lowest water level for the month is the extreme low (EL) water, while the highest water level is the extreme high (EH) water level. 43 Tide Height Statistics* Table 7 Month or Year Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 1991 1990 1989 1988 1987 1986 1985 1984 1983 1982 1981 1980 1979 1979- 1991 * Measurements are in centimeters. 49 49 46 55 60 59 64 68 58 59 59 60 57 11 Mean Sea Level 11 Mean Low Water -32 -31 -33 -24 -35 -37 -32 -30 -42 -42 -43 -43 -35 Mean Range 44 81 Prior Years 81 80 79 79 95 96 97 98 99 101 102 103 93 Extreme High 109 199 129 113 123 136 147 143 127 149 118 121 199 May Mar Apr Jan Dec Dec Oct Jan Oct Nov Mar Feb Mar 1989 -78 -77 -72 -63 -108 -93 -77 -73 -108 -110 -119 -95 -119 Feb Apr Dec Nov Jan Apr Jul Mar Feb Apr Mar Sep Mar 1980 Water Level, m ‘ao “Py Pl lyse £ oO 404 s = | 3 4) eye A su so Hl re) 2.0 My MLW -—40 -60 i K -80 / EL -100 -120 ™ T T T roa T ] 2 1.254 Ss == 1991 1979-91 1.00-4 ORZDi1 OS0L) OR2Z5 =) 0.00 =(0) 25) =) -0.50-+ SORial -1.00- an -1.25- : 6 et ee ee T T T T T T aolee jek ap al 0.01 0.10 1.00 10.00 25.00 50.00 75.00 90.00 99.00 99.90 99.99 Percent Greater Than Figure 18. Distributions of hourly tide heights and high- and low-water levels 45 PART VI: WATER CHARACTERISTICS 52. Monthly averages of daily measurements of surface water tempera— ture, visibility, and density at the seaward end of the FRF pier are given in Table 8. The summaries represent single observations made near 0700 EST and, therefore, may not reflect daily average conditions since such characteristics can change within a 24-hr period. Large temperature variations were common when there were large differences between the air and water temperatures and variations in wind direction. From past experience, persistent onshore winds move warmer surface water toward the shoreline, although offshore winds cause colder bottom water to circulate shoreward, resulting in lower temperatures. Table 8 Mean Surface Water Characteristics Temperature Visibility Density deg C m g/cm? 1980- 1980- 1980- Month 1991 1991 1991 _1991 1991 1991 Jan 8.9 6.1 1.6 1.3 1.0223 1.0234 Feb Oeil 5.6 2.2 1.8 1.0228 1.0232 Mar 10.1 Derk 1.7 1.6 1.0225 1.0229 Apr 12.5 balck 2.5 2.3 1.0219 1.0225 May 17.6 15.5 2.5 2.4 1.0211 1.0221 Jun 22.4 19.6 2.6 3.4 1.0202 1.0214 Jul 23.6 22.1 4.8 3.8 1.0213 1.0214 Aug 25 Zo89) 2.7 3.2 1.0206 1.0204 Sep 23.9 23.1 2.7 2.3 1.0212 1.0209 Oct Ao ale) a5) 1.8 1.6 1.0218 1.0217 Nov 13.9 14.8 1.2 1.1 1.0237 1.0229 Dec 11.7 10.1 1.3 atoal 1.0248 1.0235 Annual 16.6 14.9 2.3 2.1 1.0220 1.0222 Temperature 53. Daily sea surface water temperatures (Figure 19) were measured with an NOS water sampler and thermometer. Monthly mean water temperatures (Table 8) varied with the air temperatures (see Table 2). 46 Temperature 30.0 Year eg C x—x 1991 16.6 @----o 1980-91 14.9 25.0 20.0 15.0 Water Temperature, deg C 5.0 0.0 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 19. Daily water temperature values with monthly means Visibility 54. Visibility in coastal nearshore waters depends on the amount of salts, soluble organic material, detritus, living organisms, and inorganic particles in the water. These dissolved and suspended materials change the absorption and attenuation characteristics of the water that vary daily and yearly. 55. Visibility was measured with a 0.3-m—diam Secchi disk, and similar to water temperature, variation was related to onshore and offshore winds. Onshore winds moved warm clear surface water toward shore, whereas offshore winds brought up colder bottom water with large concentrations of suspended matter. Figure 20 presents the daily and monthly mean surface visibility values for the year. Large variations were common, and visibility less than 1 m was expected in any month. Monthly means are given in Table 8. 47 Year Mean, m 7.0 *—* 1991 2.3 : e----0 1980-91 2.1 Water Visibility, m JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 20. Daily water visibility values with monthly means Density 56. Daily and monthly mean surface density values, plotted in Figure 21, were measured with a hydrometer. Monthly means are also given in Table 8. 48 Density, g/em* Year Mean, g/cm> wee x—x 1991 1.0220 O--=-© 1980-91 1.0222 1.029 1.028 1.027 1.026 Se JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 21. Daily water density values with monthly means 49 PART VII: SURVEYS 57. Waves and currents interacting with bottom sediments produce changes in the beach and nearshore bathymetry. These changes can occur very rapidly in response to storms, or slowly as a result of persistent but less forceful seasonal variations in wave and current conditions. 58. Nearshore bathymetry at the FRF is characterized by regular shore— parallel contours, a moderate slope, and a barred surf zone (usually an outer storm bar in water depths of about 4.5 m and an inner bar in water depths between 1.0 and 2.0 m). This pattern is interrupted in the immediate vicinity of the pier where a permanent trough runs under much of the pier, ending in a scour hole where depths can be up to 3.0 m greater than the adjacent bottom (Figure 22). This trough, which apparently is the result of the interaction of waves and currents with the pilings, varies in shape and depth with chang— ing wave and current conditions. The effect of the pier on shore-parallel contours occurs as far as 300 m away, and the shoreline may be affected up to 350 m from the pier (Miller, Birkemeier, and DeWall 1983). Figure 22. Permanent trough under the FRF pier, 23 September 1991 50 59. Approximately once a month, surveys were conducted of an area extending 600 m north and south of the pier and approximately 950 m offshore. This was done in order to document the temporal and spatial variability in bathymetry. Contour maps resulting from these surveys, along with plots of change in elevation between surveys, are given in Appendix A. 60. All surveys used the Coastal Research Amphibious Buggy (CRAB), a 10.7-m-tall amphibious tripod described by Birkemeier and Mason (1984), and a Geodimeter electronic surveying system, a Geodimeter 140-T self—tracking, electronic theodolite, distance meter. The profile locations are shown in each figure in Appendix A. Monthly soundings along both sides of the FRF pier were collected by lowering a weighted measuring tape to the bottom and recording the distance below the pier deck. Soundings were taken midway between the pier pilings to minimize errors caused by scour near the pilings. 61. A history of bottom elevations below Gages 645 and 625 is presented in Figure 23 for pier stations 7+80 (238 m) and 18+60 (567 m), along with intermediate locations, 323 and 433 m. Distance (m) 238 Depth, m 323 433 567 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure 23. Time history of bottom elevations at selected locations under the FRF pier 51 PART VIII: PHOTOGRAPHY Aerial Photographs 62. Aerial photographs were taken biannually using a 23-cm aerial mapping camera at a scale of 1:12,000. All coverage was at least 60-percent overlap, with flights flown as closely as possible to low tide between 1000 and 1400 EST with less than 10-percent cloud cover. The flight lines covered are shown in Figure 24. Figure 25 is a sample of the imagery obtained on 23 January 1990; the available aerial photographs for the year are: Date Flight Lines Format 14 Jan 1 B/W 2 Color Beach Photographs 63. Daily color slides of the beach were taken using a 35-mm camera from the same location on the pier looking north and south (Figure 26). The location from which each picture was taken, as well as the date, time, anda brief description of the picture, were marked on each of the slides. 52 ~ ALBEMARLE SOUND ES See CHESALEANKE BAY eS FB oO eS Om A a PAML/ICO SOUND CAE IW TERA S Figure 24. Aerial photography flight lines 53 Figure 25. Sample aerial photograph, 23 January 1990 (Scale = 1:12,000) 54 North View South View b. 10 February 1991 ¢. 10) Mareh 1991) Figure 26. Beach photos looking north and south from the FRF pier : (Sheet 1 of 4) 55 North View South View s Se ..... f. 5 June 1991 Figure 26. (Sheet 2 of 4) 56 North View South View g. 10 July 1991 h. 10 August 1991 he 10 September 1991 Figure 26. (Sheet 3 of 4) 57 North View South View j. 10 October 1991 k. 11 November 1991 1. 8 December 1991 Figure 26. (Sheet 4 of 4) 58 PART IX: STORMS 64. This section discusses storms (defined here as times when the wave height parameter, H,, , equaled or exceeded 2 m at the seaward end of the FRF pier). Sample spectra from Gage 630 are given in Appendix B. Prestorm and/or poststorm bathymetry diagrams are given in Appendix A. Tracking information was provided by NOAA Daily Weather Maps (US Department of Commerce 1991). 59 7-9 January 1991 (Figure 27 65. Winds from a strong Canadian high-pressure system began to generate storm waves at the FRF late on 7 January. Development of a weak coastal storm off the Georgia coast early on 8 January prolonged the period of onshore winds. The maximum H,, (at Gage 625) of 2.96 m (T, = 10.67 sec) was attained at 2342 EST on 8 January. Maximum winds (from the northeast) approaching 15 m/s occurred at 2042 EST on 7 January. 1040 Atmospheric Pressure, mb Gage 616 vel 10204 Ta i ae oe ei 1000 99.0 tt tes ray 255 Wind Speed, m/sec Gage 932 360-5 Wind Direction, Deg True N 3) 180 904 Gage 633 a Wave Direction, Deg True N Gage 3511 35 Wave Height, H,,,, m Gage 625 ee 20- Wave Period, T,, sec Gage 625 NA I 6 7 8 9 10 i} JANUARY, 1991 Figure 27. Data for 7-9 January 1991 storm 60 11-12 January 1991 (Figure 28 66. Following directly behind the storm on 8 January, another Canadian high-pressure system briefly regenerated storm waves at the FRF. Maximum winds (from the southeast) exceeding 13 m/s peaked at 2042 EST on 11 January with the maximum H,, (at Gage 625) of 2.25 m (T, = 8.83 sec) occurring early the next day at 0100 EST. 1040 Atmospheric Pressure, mb Gage 616 el Bo 205 seein a ate wna ve 10104 10004 99 Ot ood 255 Wind Speed, m/sec Gage 932 06 SS SSS SSS Se! 3605 Wind Direction, Deg True N Gage 633 270-4 18074 304 a aaa a a Te aS SS Sl 160- Wave Direction, Deg True N Gage 3511 1004 40-5 NJ — . -204 35 Wave Height, H,,. ™ Gage 625 24 hese pea Bets ny ween 4 pa een SS a IS 205 Wave Period. T,, sec Gage 625 Water Level from NGVD, m YI ooo] 10 11 12 13 14 JANUARY, 1991 Figure 28. Data for 11-12 January 1991 storm 61 23 February 1991 (Figure 29) 67. Developing in the Gulf of Mexico off Texas on 20 February, this weak storm slowly moved across the southern U.S., being located over South Carolina on 23 February and moving offshore the following day. Peak winds (from the north-northeast) approached 16 m/s at 0508 EST on 23 February. The maximum H,, (at Gage 625), which was recorded later that day at 1900 EST, reached 2.30 m (T, = 7.53 sec). The minimum atmospheric pressure of 1,003.4 mb occurred at 1708 EST on 22 February. There was no precipitation at the FRF from this storm. 1040 Atmospheric Pressure, mb Gage 616 ex 1020 10104 RA Ngo cam ON REY cit ee 10004 999. Ot ro at 25-4 Wind Speed, m/sec Gage 932 3605 Wind Direction, Deg True N Gage 633 2705) oigira wane eae 180-4 Wave Direction, Deg True N Gage 3511 Se Wave Height, H,,5. ™ Gage 625 205 Wave Period, T,, sec Gage 625 0d eS SSS eS SS SSS 2 Water Level from NGVD, m Gage 1 4 sO = YE Se IN ae SS SSS SS SS SSS 22 23 24 25 FEBRUARY, 1991 Figure 29. Data for 23 February 1991 storm 62 6-7 March 1991 (Figure 30) 68. Winds from a strong Canadian high-pressure system began to generate storm waves at the FRF late on 6 March. The maximum H,, (at Gage 625) of 2.50 m (T, = 7.53 sec) was attained at 0208 EST on 7 March. Maximum winds (from the northeast) exceeding 16 m/s occurred at 0542 EST also on 7 March. 1040. Atmospheric Pressure, mb Gage 616 1010: 1000 eee Shs a eR mt) yy 255 Wind Speed, m/sec Gage 932 CY) 360- Wind Direction. Deg True N a 2704 1804 90 As i Solas are Sieg Wave Direction, Deg True * 4nes ‘] Wave Period, ~,, sec Gage 625 5 No 104 Sis ht OC eta cee aim s4 0 : enV en om Te To CT To Tm ToT ze Water Level fom NGVD, r Gage 1 | 5 6 7 8 9 MARCH, 1991 Figure 30. Data for 6-7 March 1991 storm 63 29 March 1991 (Figure 31) 69. Developing over South Carolina on 29 March, this storm rapidly moved to the northeast, being located off the Virginia coast by 30 March. Maximum winds approaching 16 m/s peaked at 1634 EST on 29 March with the maximum H,, (at Gage 625) of 2.22 m (T, = 6.92 sec) occurring later the same day at 1934 EST. The minimum atmospheric pressure of 1,014.0 mb was recorded at 0400 EST on 30 March. Total precipitation was 30 mn. 1040 Atmospheric Pressure, mb Gage 616 1030 1020 1010 1000 990 : Wind Speed, m/sec 360-5 Wind Direction, Deg True N Oy Wave Direction, Deg True N Gage 3511 Gage 625 a —— 20 Wave Period, T,, sec Gage 625 ———————— eS i pi er I rc pe 2 Water Level from NGVD. m MARCH, 1991 Figure 31. Data for 29 March 1991 storm 64 20-21 April 1991 (Figure 32) 70. Developing off Cape Hatteras, NC on 20 April, this intense coastal storm quickly deepened and moved up the coast, being located off the Maryland coast early on 21 April and over Canada by 22 April. Maximum wind speeds near 17 m/s (from the north-northeast) were recorded at 1600 EST on 20 April, with the maximum H,. (at Gage 625) of 2.81 m (T, = 8.83 sec) occurring several hours later at 2020 EST. This was followed the next morning at 0208 EST by the minimum atmospheric pressure of 998.4 mb. Total precipitation at the FRF from this system was 42 mn. 10405 Atmospheric Pressure, mb Gage 616 1030-4 10204 10104 10004 Wind Speed, m/sec Gage 932 a) : 360- Wind Direction, Deg True N 270+ 1804 904 0+— ea SS T 1605 Siave Direction. Deg True N Sage 3513 1004 —— SSS 40 35 wave Height, +,,, m Sage 625 20-7 wave Periog, > 154 ee s4 sec Sage 625 a Kas T ce Uo eT UT TT Te Te Tolono foo Ce oe #iater Level from NGVD, m Sage 1 Ne aS APRIL, 1991 Figure 32. Data for 20-21 April 1991 storm 65 18-19 May 1991 (Figure 33 71. Winds from a strong Canadian high-pressure system began to generate storm waves at the FRF late on 18 May. The maximum H,, (at Gage 625) of 2.43 m (T, = 6.92 sec) was attained at 1000 EST on 19 May. Maximum winds (from the northeast) neared 14 m/s at 0842 EST, also on 19 May. 1040 Atmospheric Pressure, mb Gage 616 1030 1020 1010 1000 990 25 Wind Speed, m/sec Gage 932 20 i} 10 s C) 360. Wind Direction, Deg True N Gage 633 270 180 90 0 a Sl 160 Wave Direction, Deg True N Gage 3511 100 ~ A a a ae -20 3 Wave Height, H,,,, m Gage 625 Aare ai 4 5 SSS a SS 20-5 Wave Period, T,, sec Gage 625 25 Water Level from NGVD, m Gage 1 | — oS SSS SSS SS SS SS SS SSS SS SS 7 18 19 20 21 MAY, 1991 Figure 33. Data for 18-19 May 1991 storm 66 23 June 1991 (Figure 34) 72. Development of a weak coastal storm off the North Carolina coast early on 22 June produced a short period of storm waves. The maximum H,, (at Gage 625) of 2.43 m (T, = 8.26 sec) was attained at 2042 EST on 23 June. This coincided with the maximum winds (from the north-northeast) which exceeded 14 m/s and occurred at 2008 EST. The minimum atmospheric pressure of 1,006.3 mb was recorded on 22 June at 1900 EST. Total precipitation was 25 mm. 1040 Atmospheric Pressure, mb Gage 616 1020 1010: 25 Wind Speed, m/sec Gage 932 20 1S 10 5 ° 360 Wind Direction. Deg True N Gage 633 270 180 90 0 - 160 Wave Direction, Deg True N Gage 3511 100. 40 -20 3 Wave Height. H,,,, m Gage 625 205 Wave Period, T,, sec Gage 625 2 Water Level from NGVD, m Gage 1 1 -1 SS SS a SSS 22 23 24 25 JUNE, 1991 Figure 34. Data for 23 June 1991 storm 67 18-19 August 1991 —" Hurricane Bob" (Figure 35 73. Bob reached tropical storm intensity on 16 August while located close to Bermuda and was upgraded to a hurricane on 17 August. The storm continued to intensify as it rapidly moved up the east coast, developing into a Category 3 hurricane (winds of 50 — 58 m/s (111 to 130 mph) on the Saffir/Simpson hurricane scale) as the eye passed 25 — 30 miles (40 — 48 km) east of Cape Hatteras, NC early on 19 August. Continuing up the coast, the storm finally made landfall on the Rhode Island coast late on 19 August. The maximum H,,. (at Gage 630) of 4.83 m (T, = 15.06 sec) was recorded at 2342 EST on 18 August. Maximum onshore winds (from the northeast) approached 15 m/s occurring several hours earlier at 1934 EST. Peak winds (from the northwest) exceeded 23 m/s near midnight on 18 August. This coincided with the minimum atmospheric pressure of 994.0 mb. Total precipitation was 43 mn. toao, Atmospheric Pressure, mb Gage 616 990+ lalalatalatalaleaeal 254 Wind Speed, m/sec 360, Wind Direction, Deg True N Wave Height, H,,,, m Gage 630 ‘ 34 24 Zz ra ee Sara RUT Tao ay, To Tae Tea Taal ~y Wave Period, T,, sec Gage 630 154 104 (Gana emer See Oe 5 Oh SU + T Colarton rans Tt 2, Water Level from NGVD, m Gage 1 4 ele ABN ENG AYE ° SS + SAL A SLL Sa 7 18 19 20 21 AUGUST, 1991 Figure 35. Data for Hurricane Bob, 18-19 August 1991 68 25 August 1991 (Figure 36) 74. A Canadian high-pressure system briefly produced storm waves at the FRF on 25 August. Maximum winds (from the northeast) exceeding 13 m/s peaked at 1708 EST on 25 August, with the maximum H,, (at Gage 625) of 2.19 m (T, = 6.40 sec) occurring several minutes later at 1742 EST. 1040 Atmospheric Pressure, mb Gage 616 9 EE 25 Wind Speed, m/sec Gage 932 20 Ss : Pe epi) eras 5 ° 360 Wind Direction, Deg True N Gage 633 160 A Wave we Deg True N Gage 3511 / 3 Wave Height, H,,,4. 7 Gage 625 20 Wave Period, Tp. sec Goge 625 Water Level from NGVD. m 24 25 26 27 AUGUST, 1991 Figure 36. Data for 25 August 1991 storm 69 1-2 September 1991 (Figure 37) 75. A strong Canadian high-pressure system generated storm waves at the FRF on 1-2 September. Maximum winds (from the northeast) approached 15 m/s peaking at 1300 EST on 1 September with the maximum H,, (at Gage 625) of 2.47 m (T, = 8.00 sec) occurring several hours later at 1742 EST. 10405 Atmospheric Pressure, mb Gage 616 10304 10204 SM Mine Serer ae a Lie eRe ee eae 10104 10004 99 Oe Wind Speed, m/sec Gage 932 ee Se | 360 Wind Direction, Deg True N Gage 633 Wave Direction, Deg True N Gage 3511 35 Wave Height, H,5. ™ Gage 625 205 Wave Period, T,, sec Gage 625 a a a 1 2 3 4 SEPTEMBER, 1991 Figure 37. Data for 1-2 September 1991 storm 70 20 September 1991 (Figure 38 76. A Midwestern high-pressure system briefly produced storm waves at the FRF on 20 September. Maximum winds (from the northwest) exceeding 16 m/s were recorded at 1000 EST on 20 September with the maximum H,, (at Gage 625) ofe2= 2 came Gh a7 ll sec) (occuLmi np ac yl 216 7EST) Ce a a a a SC se es sc ne ee en | 25- Wind Speed, m/sec Gage 932 3605 Wind Direction, Deg True N 2704 1804 | 905 1605 Wave Direction, Deg True N Gage 3511 1004 f————_—~ = NV (a7 ts ras aeopemancminnar es -204 3, Wave Height. H,,,. m Gage 625 2 Water Level from NGVD, m Gage 1 19 20 21 22 SEPTEMBER, 1991 Figure 38. Data for 20 September 1991 storm 71 3 October 1991 (Figure 39 77. Developing over southern Florida early on 1 October, this small coastal storm slowly moved up the eastern coast, being located off Cape Hatteras, NC on the morning of 3 October. Rapidly picking up speed, the storm was located off the Maine coast early the next day. The maximum H,, (at Gage 625) of 2.34 m (T, = 5.69 sec) occurred at 0916 EST on 3 October. 10405 Atmospheric Pressure, mb Gage 616 10304 10204 es 10104 oo. ee ee eee 100074 255 Wind Speed, m/sec Gage 932 2704 904 i a I od 160 Wave Direction. Deg True N Gage 3511 OO pa ee RR NON 404 ie -204 35 Wave Height, F..,, m Gage 625 24 Vas 4 Nate oo ween ees aE | 0 oro th oo 205 Wave Period, 7., sec Gage 625 1S i eNO Noe ARI NT ON IIT s4 0 2 Water Level from NGVD, m Gage | | GI ORIN ~ Sa Soa =1 2 3 4 5 OCTOBER, 1991 Figure 39. Data for 3 October 1991 storm 72 16-17 October 1991 (Figure 40) 78. Forming over Texas on 14 October this storm slowly travelled across the southeastern United States, moving into the Atlantic on 16 October. Located off South Carolina, the storm rapidly intensified beginning a northerly track up the coast. By 18 October the storm was located off the Maine coast. Peak onshore winds exceeding 15 m/s (from the northeast) were recorded at 2308 EST on 16 October with the maximum H,, (at Gage 625) of 2.63 m (T,; = 7.31 sec) following at 2342 EST. The minimum atmospheric pressure of 1,004.7 mb occurred on 17 October at 0434 EST. Precipitation was 56 mm. 1040 Atmospheric Pressure, mb Gage 616 nara Skis banags acd t el nee hada ate oe 25 Wind Speed, m/sec Gage 932 Wind Direction, Deg True N Gage .633 160 Wave Direction, Deg True N Gage 3511 3 Wave Height, H.,. m Gage 625 FS 20-7 Wave Period, T,, sec Gage 625 aaa Tonto SS | 24 Water Level from NGVD, m Gage 1 1 SS d Va a Ye ESI LEN S| Se = a Toles [aoa SS | 15 16 17 18 19 OCTOBER, 1991 Figure 40. Data for 16-17 October 1991 storm 73 28 October - 1 November 1991 - "Halloween Storm" (Figure 41 79. ("Halloween Storm") - This major storm, which was similar in many respects to the 1962 "Ash Wednesday" storm, was actually a sequence of events which began with a hurricane. Early on 27 October, Hurricane Grace approached the southeastern U.S. coast. While still well out to sea, Grace curved to the north, following a track that paralleled the coast but kept her well offshore. By the morning of 28 October, Grace was located approximately 1,000 kilometers east of the North Carolina coast where she encountered a strong easterly moving Canadian high-pressure system. The collision of these two systems produced high onshore winds at the FRF. Augmented by these strong winds, large waves, which were produced well offshore by Hurricane Grace, continued to build as they approached the North Carolina coast; wave heights recorded at the FRF increased throughout the day. Grace continued to track north, finally being absorbed by a low-pressure system located off Nova Scotia late on 29 October. The merging of these two systems produced a huge storm which, contrary to normal storm tracks, proceeded to slowly move to the southwest. Early on 30 October the storm was off the New England coast and generating hurricane-force winds with a central atmospheric pressure of 988 mb as it continued its slow southwesterly course. By the morning of 31 October the storm was located well off the Maryland shore; although still strong, it had begun to weaken with its southwesterly movement greatly reduced. November 1 found the storm reversing its course and moving back out to sea as it continued to weaken. By the morning of November 2, the storm had curved back to the north; however, by the time the storm crossed the Maine coast, it had weakened considerably. 80. Although only a few oceanfront structures on the Outer Banks were completely destroyed, there was heavy damage to the primary dune system as well as extensive flooding and ocean overwash. Much of the sediment removed from the dunes was deposited inland burying most of an oceanfront road, while the flooding made many other roads impassable for over a week. Much heavier damage was reported to areas north of the Outer Banks, especially along the New England coast. 81. Maximum wind speeds at the FRF approached 18 m/s at 1600 EST on 28 October while the maximum H,, (at Gage 630) of 5.93 m (T, = 19.69 sec) occurred at 0016 EST on 31 October. The minimum atmospheric pressure at the 74 FRF only fell to 1,004.7 mb. This was a result of the storm center remaining well offshore. There was no precipitation at the FRF from this storm. 82. This storm encompassed several interesting features. Waves with an Hj. above 2.0 m (at Gage 625) lasted for 101 consecutive hours. The maximum i reached 21.33 sec on 30 October, while waves with T, above 15 sec (normally only associated with hurricanes) were recorded both on 30 and 31 October, long after Hurricane Grace had passed. The storm surge at the FRF approached 0.7 m, with the highest tide level reaching +1.53 m (NGVD) on 31 October. 1040 Atmospheric Pressure, mb GAGE 616 25 Wind Speed, m/sec GAGE 932 Wind Direction, Deg True N GAGE 633 150 Wave Direction, Deg True N GAGE 3111 Wave Height, H,j5, GAGE 630 Wave Period, Tp GAGE 630 Water Level from NGVD, m GAGE 1 28 29 31 1 30 2 OCTOBER NOVEMBER 1991 Figure 41. Data for 28 October-1 November 1991 storm 75 8-10 November 1991 (Figure 42) 83. Developing off Florida on 7 November, this storm slowly moved up the coast being located near Cape Hatteras, NC early on 10 November and reaching New England by 12 November. Maximum wind speeds (from the northeast) exceeded 21 m/s at 1600 EST on 9 November followed by the peak H,, (at Gage 625), which reached 3.49 m (T, = 12.19 sec) at 2234 EST. The minimum atmospheric pressure of 1,003.3 mb was recorded at 0508 EST on 10 November. Total precipitation was 39 mm. 1040 Atmospheric Pressure, mb Gage 616 1030 1020 1010 Se mn ee ee ee 1000 990 25 Wind Speed, m/sec Gage 932 20 1S 3 WOE RRS s C) 360 Wind Direction, Deg True N Gage 633 270 Wee ene 180 90 ae 0 TN tt ood 160 Wave Direction, Deg True N Gage 3511 100 | wr CALNE 40 -20 4 Wave Height. H,,,. m Gage 625 20 Wave Period, Tp: sec Gage 625 be pb leate Mae Naas Seve INGO Nn 2 Water Level from NGVD, m Gage 1 EWA 7 Pst AN APOI A 7 8 9 10 ih 12 NOVEMBER, 1991 Figure 42. Data for 8-10 November 1991 storm 76 19 December 1991 (Figure 43) 84. A strong high-pressure system centered over the Creat Lakes briefly generated storm waves at the FRF on 19 December. The peak wind speed (from the north-northwest) which surpassed 15 m/s was recorded at 1216 EST on 19 December. The maximum H,, (at Gage 625) of 2.18 m (I, = 7.31 sec) occurred several hours earlier at 1034 EST. 1040 Atmospheric Pressure, mb Gage 616 el 1020 on 1000 a | 255 Wind Speed, m/sec Gage 932 204 154 104 s4 a 360 Wind Direction, Deg True N Gage 633 *| | 1304 | 904 Te 160. Wave Direction, Deg True N Gage 3511 100 ————_ ; Sey tee ew itera re -20 4 3 Wave Height, H_,.,. m Gage 625 2 1 : -” 204 Wave Period, T,, sec Sage 625 25 Water Level from NGVD, m Gage | 18 19 20 21 DECEMBER, 1991 Figure 43. Data for 19 December 1991 storm 77 31 December 1991 (Figure 44) 85. Another strong high-pressure system centered over the Great Lakes again generated storm waves at the FRF for a brief time on 31 December. The was recorded at The maximum H,, (at Gage 625) of 2.07 m lis oe 10.67 sec) occurred several hours later at 1742 EST. peak wind speed (from the northeast) which exceeded 12 m/s, 0734 EST on 31 December. 1040. Atmospheric Pressure, mb Gage 616 1030 1020 1010 1000 mi Wind Speed, m/sec Gage 932 360 Wind Direction, Deg True N Gage 633 z at to) VT Wawneae ‘ bait r 1 oy Wave Direction, Deg True N Gage 351 1203] oT sere ~-rerer-.—a—SS—[va_>_>w= SS -204 35 Wave Height, H,,,, 7 Gage 625 ES al pea ae | (ee ee : Gage 625 205 Wave Period, T,, sec ig 1s4 ne =a a ———__ 4 IN 10 2 ee See \ pe ~~ AN, nd Ga] UH F) ease SSS a 7 25 Water Level from NGVD, m Gage | i rN a ee ole — apa NT ae | 29 30 30 -=CEMBER, 1991 Figure 44. Data for 31 December 1991 storm 78 REFERENCES Bingham, C., Godfrey, M. D., and Tukey, J. W. 1967. "Modern Techniques of Power Spectrum Estimation," IEEE Trans. Audio Electroacoustics, AU-15, pp 56—- 66. Birkemeier, W. A., and Mason, C. 1984. "The CRAB: A Unique Nearshore Surveying Vehicle," Journal of Surveying Engineering, American Society of Civil Engineers, Vol 110, No. 1. Field Research Facility. 1991 (Jan-Dec). "Preliminary Data Summary," Monthly Series, Coastal Engineering Research Center, US Army Engineer Waterways Experiment Station, Vicksburg, MS. Grogg, W. E., Jr. 1986. "Calibration and Stability Characteristics of the Baylor Staff Wave Gage," Miscellaneous Paper CERC-86-7, US Army Engineer Waterways Experiment Station, Vicksburg, MS. Miller, H. C. 1980. "Instrumentation at CERC’s Field Research Facility, Duck, North Carolina," CERC Miscellaneous Report 80-8, US Army Engineer Waterways Experiment Station, Vicksburg, MS. Miller, H. C., Birkemeier, W. A., and DeWall, A. E. 1983. "Effect of the CERC Research Pier on Nearshore Processes," Coastal Structures '83, American Society of Civil Engineers, Arlington, VA, pp 769-785. US Department of Commerce. 1987. "Daily Weather Maps," Weekly Series, Washington, DC. Welch, P. D. 1967. "The Use of Fast Fourier Transform for the Estimation of Power Spectra: A Method Based on Time Averaging Over Short Modified Periodograms," IEEE Trans. Audio Electroacoustics, AE-15, pp 70-73. 79 i th iy a » } a _ :.. at co heyy * i 4 2 ‘ Eyed ~ " eet , meh AIT BES oNGe i {tare eT eT er ees. f f * a 4 3 i Bs) creeped & i pri . ” ’ ' . tt ; i 3) on ‘ bol thar he BT rf rt Ly 5 ! ’ +h I Be SH : Uh Hap i i ial ¥ y eek pi x » i rey a : Pat : : asian 4 ta ‘ : fa Me ; ; 7 ve 9 : Y . i ; OUT eds \ i i eh n R APPENDIX A: SURVEY DATA 1. Contour diagrams constructed from the bathymetric survey data are presented in this appendix. The profile lines surveyed are identified on each diagram. Contours are in %-meter increments referenced to the National Geodetic Vertical Datum (NGVD). The distance offshore is referenced to the Field Research Facility (FRF) monumentation baseline behind the dune. 2. Changes in FRF bathymetry diagrams constructed by contouring the difference between two contour diagrams are also presented with contour inter— vals of 0.25 m. Wide contour lines show areas of erosion. Other areas correspond to areas of accretion. Although these change diagrams are based on considerable interpolation of the original survey data, they do facilitate comparison of the contour diagrams. Al ! » \ 9.0.0) RY) L l RRR oO ! .) a u RR ! XR . oe y BN Wateeraateatadca XQ % Le ! SRR RRR C SRR SS RRA BESSA RRRY Nn tr O nM O W o O© wo on &% 850 FRF Pier 650 31 Oct 90 (0.25 m Contours) Distance, m ® cS) = a) ” o D c ie} fe O 450 25—~ VS 05-9 PO 4 i = 2262-0-205-9O 92 = bn =) 2 £7 = — 250 Wi ‘edUDISIG SUBQUINN aUlq ajlsoud no mn Oo - ~+~o mri nNdNnwn oOo RnR DO OD 2M 0 KR KR KR KR © © © © © © O O oe 2S BSE SF seg8uetgsesat ease 850 FRF Bathymetry 18 January 91 (depths relative to NGVD) 1100 1000 900 800 Oo wo wo E © (6) c oS) 2 2 +O d é Oo fy wo N oO wo 700 600 500 400 300 200 0 -100 lu ‘aoduDIsIGg A2 lu ‘e9uUD{sSIG ose 0S9 osy 49!d 4Y4 (Sanojuog Wi Gz"0) L6 USP Bt aouls sebupy9 ose, OSS (GADN 07 eATIETEA sudep) T6 yOTeW zz ArjeuAUQeG sua *zW ammbty lu ‘aduDISIG SASQUINN Sul] sf!fO4d lw ‘aouDd{siq osy ool- 002 oo¢ oor 009 ooz 008 006 0001 ooll lw ‘aouDISIGg A3 FRF Pier os oO 2 0 S} a oo —- 3 5 mf 5S \) oO faa °o % > = a) RRR RR £ be © PRR Sw E RRS KO? O RS Ng : KXS> HRY Xs Ne) “s S, 2 oO ISAK) 9 ne ° <3 Qa o wo N < \ = 2 = & 3 oOo oOo o oOo o oOo oO o oO Oo oO o Co wi =) =) o fo) (=) o o ° (=) ro) °o o = ° Co) co nN o 9) ~ » nN = i lu ‘eouDIsSIGg SASQUINN BUI] aI!JO4g no Mm Oo So © & e Aw & © fF & & OA Vs SE BR © MW ® & o 0 0 0 © © © 0 nnoowoeo KR erewooao tne ee ee ee ee hee FRF Bathymetry 22 April 91 (depths relative to NGVD) Distance, m Figure A3. 1100 1000 900 800 700 300 200 100 oO Oo lo} oO oO fo} o wo st ul ‘adUDISsIG A4 FRF Pier “— Oo @ © 0 Os fe Ene ® ATS a n 26 a o < oc o Dan = © fe N cQw a .o) N © a ong oO g S wm oo 9 o nS) TD a oO -_— w : 8 i 3 8 w S 3 d SJAQWINN 2Ul7 2]!}O4q no woo —-w7t onorzwuaqan nono oOo Oran wtOnR™M © re) nM 6 oO oO oOR KR oe 2 eS RSs BS ES PS Oe Sn OS. ee - a Coy) eal 8 cs wo (+0) a N io) i 3 p wo 3 ee 5) < oS re < A em) oO wo N (o} fl wn o Oo lo} Oo lo} o Oo lo} oO oO lo} oO oO Oo oO oO oO oO oO oO oO oO oO oO Oo = Oo a 0 ~ o wo st m N = WT lu ‘aouDIsIq A5 Ye) fo) 900 800 700 24 May 91 (0.25 m Contours) FRF Pier oO (8) = 7) ” 0) D iS Lo) -S O Wi ‘eouD{siq SUBQUINN @UIT a]!}O4g oOo wMmoOo - +o orewnw mM mo nM wo ~ ne we KR CO OO WO - = a 185 186 187 600 500 400 300 200 Ww ‘aouD{siq A6 100 188 189 -100 850 650 450 Distance, m 250 50 450 650 850 Distance, m 250 50 FRF Bathymetry 27 June 91 (depths relative to NGVD) Figure A5. (GADN 02 eATIeTAaX sundep) Te ATne 9z Arjoudujed WMI ‘ow amMbry WW ‘e0uDIsIG ose 0s9 osy 0sz os 00l- 002 oo¢ 4eld 4u4 aol” (sanoyuog WwW gz"0) le unr 22 aman aouls seabubu9 ; Seve INU wi ‘eouDdIsiq 681 gel 281 981 Sel eel cg L8t 8ZI 9ZI vZI LZt O91 SIBQUINN aUly afijoud w w wow Ww oar 2 DOAN YT OR YM © nwo © © O© O KR KR lu ‘a0UuDISIG Ost ool 002 009 joey 008 006 ooll lu ‘aouDIsIg A7 oOo Dm ow w 1100 WAKY \ N + oOo oO ARS SSRN o wo Nn wo Le) Kn 26 Jul 91 (0.25 m Contours) ® 6) = n ” o D < fe) ie oO JdQUINN aul] a|!}o4g - =~ © s Ss 178 FRF Pier 181 182 183 185 186 oO Oo oO oO i>) oO o wo t wi ‘adUuDIsIG A8 300 200 100 187 188 189 650 850 450 Distance, m 250 50 250 450 650 850 50 Distance, m FRF Bathymetry 23 August 91 (depths relative to NGVD) Figure A7. lu ‘e9uDIsIq ose 0s9 osy A®ld 4Y4 (sanojuog W gz'0) 16 Bny ¢Z souls sebupuy XK <\? NGO SORT (GADN 03 eATAeTeA suQdep) T6 Tequejdes ez ArjouAujed RW OSsz os WW ‘aouD{sIGg V] 8]!sO4d SUdqUINN au lu ‘aoduDIsiq OSr *sW sambTy ool- 002 oo¢ oor 00s 000! ool lw ‘aouDI sig AQ FRF Pier es Oo 8_ 5 : - 2? L cs oe o S oa O O56 7 oN cx 2 [ine Dig & fhe Ne) = io) N © <= fe} c oO wa oo 9 0 — e *% a Oo wo N 50 lw ‘adUuDISIG SHOQUWINN OUlT a[!JO4g ow wm oO Ren OO) NOLO) ete CO Ps OO) EO) mo mW oO ~n RnR KR KR DO O O O HO HO O O - - = —- Ke Ke Ke Ke Ke Ke Ke eS 95 oOo w owooo Oo O KR KF O 650 Distance, m 450 850 Figure A9. FRF Bathymetry 23 October 91 (depths relative to NGVD) 250 oO wo oO o oO oO oO fo} (fo) fo} oO oO (o} oO fo} oO (>) oO oO oO oO o oO oO (=) oO fo} = oO an 00 ~ wo wn + m N ae 7 — lu ‘aouDISsIG Al10 850 a SoS $3 ose SoS $5 oo re co ro 3S 650 Distance, m ra 5 ras $o5 23 Oct 91 (0.25 m Contours) FRF Pier SoS Ss 555 505 ieee $5 oS SSSSSOS <> 55 Soo oO cS) = 72) ” 1) D iS 2) Le oO 450 250 50 W ‘e9UDIsIGg SUBQUINN aUlq af!joud wo oOo = Le) o ~ iS _— — 181 183 186 188 co N o » iY) Te) o o n co 850 650 Distance, m 450 250 ° ° ° ° ° ° ° ° rs) ° ° ° = ° a ce) nN © 500 400 300 200 0 -100 lw ‘aouDisig All FRF Bathymetry 3 November 91 (depths relative to NGVD) Figure A10. oa cb) i oO =} > L > S ° 2 rw ADE oa XC ° KYO > a n 206 a RR os € E i) Cc wo 2 « oMn © PSE BRS SOS fe oO © = “i XY < SEIS RN S © 5 OS 4! N) 0 <= eee \ al EE iS AN) 4 9 o =< w Wi ‘aoUDIsSIGg SJOQUINN Our] a|!}O4d co N o ie) V9) RY S < 2 00 a 2 O wo o wo ~ (8) - - fs Us - — — —_ ° wo oo ° wo wo o 6) Cc 2) 2 PS S) wo N oO wo 1100 1000 900 800 700 600 500 400 300 200 100 -100 lu ‘aoUDIsIG Al2 FRF Bathymetry 12 November 91 (depths relative to NGVD) Figure All. 850 FRF Pier 12 Nov 91 (0.25 m Contours) 650 oO S) & 72) ” 0) D Cc Lo) Ls O 450 Distance, m 250 = ° ee = = > w ° ° ° ° ° °o ° ° ° ° ° ° o w ° ° ° ° ° fo) o a) (=) (=) ° o = ° a © i © 3) ~ ” a = = lw ‘eouD{SsIGg SUBQUINN 9Ulq afijoud wow nm Oo -~7+ @ompmovr NM ND Oo KR DOD OD many OonReM OH YN WY non ooeHoBR RHO DLE SSS Sf 2 eee e eee 650 850 FRF Bathymetry 18 December 91 (depths relative to NGVD) Distance, m 450 250 Figure A12. ° re) ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° ° = ° rey rm) qn o 0) + Mm a = = li “aouDIsIq A13 rie $ 14 Ses" APPENDIX B: WAVE DATA FOR GAGE 630 1. Wave data summaries for Gage 630 are presented for 1991 and for 1980 through 1991 in the following forms: Daily s Heo) and aa. 2. Figure Bl displays the individual wave height (H,,) and peak spectral wave period (T,) values, along with the monthly mean values. Joint Distributions of H,, and T, 3. Annual and monthly joint distribution tables are presented in Tables Bl and B2, and data for 1980 through 1991 are in Tables B3 and B4. Each table gives the frequency (in parts per 10,000) for which the wave height and peak period were within the specified intervals; these values can be converted to percentages by dividing by 100. Marginal totals are also included. The row total gives the number of observations out of 10,000 that fell within each specified peak period interval. The column total gives the number of observa— tions out of 10,000 that fell within each specified wave height interval. Cumulative Distributions of Wave Height 4. Annual and monthly wave height distributions for 1991 are plotted in cumulative form in Figures B2 and B3. Data for 1980 through 1991 are plotted in Figure B4. Peak Spectral Wave Period Distributions 5. Annual and monthly peak wave period T, distribution histograms for 1991 are presented in Figures B5 and Bé. Data for 1980 through 1991 are presented in Figure B/7. Bl Persistence of Wave Heights 6. Table B5 shows the number of times in 1991 when the specified wave height was equaled or exceeded at least once during each day for the duration (consecutive days). Data for 1980 through 1991 are averaged and given in Table B6. An example is shown below: Height Consecutive Day(s) or Longer ie | ge eG nian OT Gy AN) Epo as skye «Ske Gh eas 0.5 18 15 14 13 12 11. 10 9 8 1.0 50 34 24 21 18 14 12 8 7 3 2 1.5 “Ml WO & 6G 2 1 2.0 22) 95 wal 2.5 10 52 3.0 6 1 3.5 1 4.0 1 This example indicates that wave heights equaled or exceeded 1.0 m 50 times for at least 1 day; 34 times for at least 2 days; 24 times for at least 3 days, etc. Therefore, on 16 occasions the height equaled or exceeded 1.0 m for 1 day exactly (50 - 34 = 16); on 10 occasions for 2 days; on 3 occasions for 3 days, etc. Note that the height exceeded 1 m 50 times for 1 day or longer, while heights exceeded 0.5 m only 18 times for this same duration. This change in durations occurred because the longer durations of lower waves may be interspersed with shorter, but more frequent, intervals of higher waves. For example, one of the times that the wave heights exceeded 0.5 m for 16 days may have represented three times the height exceeded 1 m for shorter durations. Spectra 7. Monthly spectra for the offshore Waverider buoy (Gage 630) are presented in Figure B8. The plots show "relative" energy density as a function of wave frequency. These figures summarize the large number of spectra for each month. The figures emphasize the higher energy density associated with storms, as well as the general shifts in energy density to different frequencies. As used here, "relative" indicates the spectra have been smoothed by the three-dimensional surface drawing routine. Consequently, extremely high- and low-energy density values are modified to produce a smooth surface. The figures are not intended for quantitative measurements; however, B2 they do provide the energy density as a function of frequency relative to the other spectra for the month. 8. Monthly and annual wave statistics for Gage 630 for 1991 and for 1980 through 1991 are presented in Table B/7. 9. Figure B9 plots monthly time histories of wave height and period. B3 Wave Period, sec Wave Height, m 5.0 4.0 3.0 Year Mean, m %—x 1991 1.1 ° "Oy ere at % 2? se ge p PNAS AY 20.0 FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Year Mean, sec x—x 1991 8.3 JAN FEB MAR APR MAY JUN JUL AUG SEP OCT NOV DEC Month Figure Bl. 1991 daily wave height and period values with monthly means for Gage 630 B4 Table Bl Annual Joint Distribution of H,, versus T, eee Eee Annual 1991, Gage 630 Percent Occurrence(X100) of Height and Period OF PWWNMMRrOO Height (m) Period(sec) 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- 2.9 39 49 59 6.9 7.9 ~8.9 ~ 9.9 11.9 _13.9 _15.9 —lLonger 00 - 0.49 8 17 17 50 50 84 319 243 168 34 =126 25 50 - 0.99 17 118 285 596 655 579 982 840 974 101 218 5 00 - 1.49 : 5 84 437 269 193 537 218 176 25 92 : BOR e1e99 i Z Li Gece Ol 92 76 =: 101 17 34 ‘ 00 - 2.49 : : 5 25 118 50 42 25 25 8 : 3 WW) = 268) : q é 50 50 34 : 5 8 17 5 00 - 3.49 : : . 3 8 25 : 8 8 17 8 8 50 - 3.99 a 5 5 5 3 5 8 : 5 8 8 ‘ 00 - 4.49 : : ; : 7 7 8 8 8 a 8 -50 - 4.99 5 : 3 3 r S : 8 : : 8 .00 - Greater A 5 5 : 5 : : : i 5 3 8 Total 25 135 403 1284 1377 1082 2022 1426 1460 218 503 57 B5 Table B2 Monthly Joint Distribution of H,, versus T, ganuary 1991, Gage 630 Percent Occurrence(X100) of Height and Period Hei ght (m) Period(sec) Total OG 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- AY: A: A: WR: SO Tat eee 0.00 - 0.49 : : 3 : : ‘ : ; : . 164 ; 164 0.50 - 0.99 ; : . 328 328 164 328 1311 ; . 164 F 2623 1.00 - 1.49 6 1803 492 . 492 164 492 : : : 3443 1.50 - 1.99 : . 164 656 492 : . 328 492 : : : 2132 2.00 - 2.49 9 : . 164 . 328 . 164 164 : : c 820 2.50 - 2.99 5 : : ; ; . 492 ! : : : : 492 3.00 - 3.49 : : é : . 164 ; . 164 : j z 328 3.50 - 3.99 : ; : . : : ; ; 3 : : : 0 4.00 - 4.49 0 4.50 - 4.99 j ; : ‘ A P : ‘ : j 0 5.00 - Greater ‘ : : ; : : i : : 3 : : 0 Total 0 QO 164 2951 1312 656 1312 1967 1312 0 328 0 Sea 1991, Percent Occurrence(X100) of reveht ae Period Hei ght (m) ete See ee ae BI ee Period (Seg) ues ieee VEN Se Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- 2.9 3.9 4.9 5.9 6.9 7.9 8.9 _9.9 11.9 _13.9 _15.9 _Longer panes 0.00 - 0.49 : : . s 5 : . 800 ; 5 : ; 800 0.50 - 0.99 . 400 4 j - 400 400 800 400 3 : . 2400 1.00 - 1.49 ; A . 800 . 1200 400 5 , : : : 2400 1.50 - 1.99 3 ; - 800 400 400 400 400 : : : d 2400 2.00 - 2.49 j ; : . 800 i . 400 : : : : 1200 2.50 - 2.99 : j : . 400 400 : ; 5 A : é 800 3.00 - 3.49 j : ‘ : : : ; 5 x ‘ : : 0 3.50 - 3.99 0 4.00 - 4.49 0 4.50 - 4.99 5 5 4 5 : ; y 0 5.00 - Greater 3 P . : s x x a ? ; ; : 0 Total 0 400 0 1600 1600 2400 1200 2400 400 0 0 0 March 1991, Gage 630 Percent Occurrence(X100) of Height and Period Height (m) Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- —2.9 3,9 4,9 5.9 6.9 7.9 8.9 _9.9 11.9 _13.9 _15.9 _Longer vs 0.00 - 0.49 2 5 a : ; : : s , : ‘ i 0 0.50 - 0.99 4 85 : 85 169 85 254 678 1780 85 424 “ 3645 1.00 - 1.49 5 . 169 678 424 169 847 508 1102 85 508 F 4490 1.50 - 1.99 ; : 25433 Oh OO SS Onc 54a 339) ; : ‘ 1694 2.00 - 2.49 ‘ 3 85 ; . : : 85 : : : 170 2.50 - 2.99 i : : : . M x M ‘ 0 3.00 - 3.49 0 3.50 - 3.99 0 4.00 - 4.49 0 4.50 - 4.99 5 : ; i l 5 : : 3 : E 0 5.00 - Greater i 5 : A 5 5 : 5 S : : 0 Total 0 85 169 1102 932 423 1440 1440 3306 170 932 0 (Cont inued) (Sheet 1 of 4) B6 Table B2 (Continued) Height (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1250 = 11399 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total Height (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1.50 - 1.99 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total Height (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1.50 - 1.99 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total a a a ep OOM (SOG) MEE ae SS a A Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- — sit) — nf} 18) — 6) 88) eg) _ts6) N38) _thenerre oe 5 F ‘ z 250 250 5 5 500 167 167 667 1417 42.667 2000 583 1083 167 6918 5 : sé} Sg} 5 500 167 : " 1333 167 39333 83 167 83 833 x 83 2 : 83 166 3 83 83 : 166 83 : 83 : 0 0 : i é : ; ; : : : : 0 0 167 167 1167 2166 916 3000 1166 1083 0 167 0 May 1991, Gage 630 Percent Occurrence(X100) of Height and Period Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- Ah] — bin) (3.8) — i) S).8) ULE) leh), _ile).8) a 5 82 164 328 246 js 82 246 656 164 738 2706 82 246 820 984 656 1557 328 410 328 82 246 5739 Ps 3 164 164 246 82 164 82 : i 4 ; 902 i 82 4 82 , i 82 246 . 246 eee 82 ; ’ 328 82 , 82 ; 0 0 0 5 5 z 5 : : : 5 ‘ ; 5 82 328 1148 1558 1476 1721 656 738 984 246 1066 0 June 1991, Gage 630 Percent Occurrence(X100) of Height and Period Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0= 14.0- 16.0- — 728) iS) 48) 8) 8) 78) 8) 88) LAS) _olsin8) _lei.8)_llermrerie es f 4 94 5 94 377 566 283 5 . A 1414 F 189 566 660 472 1415 1415 943 sve (94 : 5754 : 94 189 94 377 377 94 189 5 : 5 1414 z ? 189 472 94 5 fs 377 : 1132 5 ; 5 A 189 4 5 : 189 : 94 : : 94 , ‘ p 0 3 : 0 2 : 0 3 F 5 5 ‘5 i 3 , : 5 Hf 0 0 283 1038 1226 1131 2358 2075 1792 0 94 0 (Continued) Percent Occurrence (X100) of Reet and Period April] 1991, e 630 B7 (Sheet 2 of 4) Height (m) oO oO Yoo ou oo OD OD PPWWNMNMrRRHOO wo wo .99 .00 - Greater Total APPWWNMRROO ou oO Height (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1.50 - 1.99 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total Height (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1.50 - 1.99 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total Table B2 (Continued) Percent Occurrence(X an ieee et gree rere 272710 (Sec!) eee a errata eeieedlrenes Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- a /Ao8) eho) ch 8) inf) 718) fh) 8)8) LS) 1S} n —— 5 : ‘ 172 345 1207 345 172 : 86 5 2327 259 603 1293 948 690 1638 1034 # £517 86 86172 A 7240 ; : 86 86 86 172 6 4 : : z eh ; ; : 0 i 0 3 0 5 0 B 0 2 5 : 5 : 3 F : 3 : e 0 259 603 1379 1206 1121 3017 1379 689 86 258 0 August 1991, Gage 630 Percent Occurrence(X100) of Height and Period Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- CeO SOAS RES OG EO 7 AO SEO REO OSB eONS 359 ee] Se ealonger < : z 81 163 488 569 325 163 163 2 1952 163 488 325 976 244 407 1138 2439 163 163 % 6506 2 81 81 163 81 407 163 : 5 5 976 : 3 81 163 5 : : ; ; 244 : A 81 81 81 3 oe ; 81 : : : 81 s é 3 0 2 3 0 Z F ’ 4 a F : 2 2 : 0 163 569 487 1545 569 1302 1870 2764 407 326 0 September 1991, Gage 630 Percent Occurrence(X100) of Height and Period Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- 28) si6) ORS) SE) 8) ER) eS) SUAS) ISLS) IG) _lheratetaie aks ss i 7 5 k 168 : 3 168 84 420 420 1092 1176 1176 756 84 ; 5208 : 672 168 336 1429 504 168 . , 3277 84 252 336 84 84 A 5 5 840 A 252 84 84 : E 2 420 4 84 x : : 84 sj ‘ : 0 2 $ 0 3 A 0 : : H : i 5 : Z : 3 5 a 0 0 84 1176 1092 1932 2773 1764 1092 0 84 0 (Continued) oT ate Gage 630 B8 0) of Height and Period (Sheet 3 of 4) OP PWWMMRrRrOO OPRWWNMrHHOO OPE WWMMrrOO Height (m) 00 - 0.49 50 - 0.99 00 - 1.49 50 - 1.99 00 - 2.49 50 - 2.99 00 - 3.49 50 - 3.99 00 - 4.49 50 - 4.99 .00 - Greater Total Height (m) 00 - 0.49 50 - 0.99 00 - 1.49 50 - 1.99 00 - 2.49 50 - 2.99 00 - 3.49 50 - 3.99 00 - 4.49 50 - 4.99 00 - Greater Total Height (m) 00 - 0.49 50 - 0.99 00 - 1.49 50 - 1.99 00 - 2.49 50 - 2.99 00 - 3.49 50 - 3.99 00 - 4.49 50 - 4.99 00 - Greater Tota Period(sec) Total 2.0= 3:0- 4:20- 550=) 620=) 720=820-— 9F0- 1030= 1220= 14. 0= 1630- — 2%) __\-8) — 5.8) _ 13.0) 78) fi) _ 88) 8) 181.9) 15.8) easee _ : : 164 8 5 ‘ : 82 5 328 . 2 164 246 328 164 1066 656 820 492 738 i 4674 5 : 82 328 410 2 738 246 A 82 82 : 2050 5 > 5 46 246 164 164 82 82 82 246 ‘ 1312 : . 82 82 82 82 , i % : : 328 3 i 246 4 : 82 82 410 : 3 : 6 82 164 82 82 410 a 2 5 82 82 164 5 5 82 5 82 164 5 : A : : 3 ' F : 82 82 . % a : 3 = : : : 3 ; 82 82 0 0 246 902 1312 656 2214 1066 902 984 1394 328 November 1991, Gage 630 Percent Occurrence(X100) of Height and Period Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- — Si) 26) 8) (3.8) _ 7,8) _ fe) _ 6)6) JUL) s.@ 1.9) _llemerre pee UY 5 85 : 85 2 i 763-339 85 : 85 254 1696 : 254 1186 508 678 1017 424 424 85 & 4576 4 85 508 508 254 169 254 85 85 254 : 2202 ; 169 169 85 : 2 85 : : 508 E : 169 85 F 85 ‘i F 339 : 85 85 Fi f 85 ; 255 , 85 3 ; z 85 5 4 85 5 85 5 5 85 85 170 3 : a ¢ 3 i 85 é 5 0 oe 0 85 339 1948 1439 1187 2119 1187 764 255 424 254 December 1991, Gage 630 Percent Occurrence(X100) of Height and Period Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- — 8) 38) th) Bi) 68) _ 7/8) 6.0) __8).8) NL) SL.) Ib.8) Slemerie ees 244 3 : ; ; 244 3 ; 5 2 3 : 488 244 488 244 244 976 . 1220 488 1707 5 5 ; 5611 : - 488 732 5 732 732 244 é : 244 : 3172 244 : : _ y 2 2 ; ; s 244 i 244 ; 244 rz’ 244 : 0 0 0 5 : 5 5 e 3 $ 5 b ; 5 488 488 976 976 1220 1220 1952 732 1707 0 244 0 Table B2 (Concluded) October 1991, Gage 630 B9 Percent Occurrence(X100) of Height and Period (Sheet 4 of 4) Table B3 Annual Joint Distribution of H,, versus Tp (All Years) OP PWWMMrRrOO Height (m) 00 - 0.49 50 - 0.99 00 - 1.49 50 - 1.99 00 - 2.49 50 - 2.99 00 - 3.49 50 - 3.99 00 - 4.49 50 - 4.99 .00 - Greater Total TeASols, behl a Bektn ba owe Pods, Spe rilod(isec Mutu Maint Ow i Bewel, 2.0- 4.0- 5.0- 6.0- 7.0- 8.0- —2.9 —4.9 _5.9 _6.9 _7.9 8.9 27 37 3.0- —3.9 14 136 9 159 Annual 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period 26 60 86 114 332 255 509 592 526 882 143 405 424 251 284 13. 164 «89245 «111 83 1 24 95 67 54 1 12 i 1. 7G 2 i 438 1163 1455 1114 1674 9.0- —9.9 — w 10.0- 12.0- 14.0- 16.0- 11.9 _13.9 _15.9 Pee RK RRR hwoMu B10 Table B4 Monthly Joint Distribution of H,, versus T, (All Years) Pp January 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period Hei ght (m) Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- Vote 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- fe) SG) AUG) Bie) 8) pO On Oem n 9 ie Oh Se Oe 529 palonger: 0.00 - 0.49 88 8 8 80 72 40 151 247 215 48 96 1053 0.50 - 0.99 72 207 +231 +406 406 351 351 709 829 104 223 3889 1.00 - 1.49 16 159 598 534 247 207 199 486 24 8 2534 1.50 - 1.99 32 335 414 183 96 104 231 24 48 1467 2.00 - 2.49 S22 il7/s) ANS} 96 32 104 32 24 8 686 2.50 - 2.99 16 64 64 16 64 16 40 280 3.00 - 3.49 16 24 8 32 80 3.50 - 3.99 : 5 0 4.00 - 4.49 : 8 8 4.50 - 4.99 : Q ; : 5 F : 8 A ‘ ; 8 5.00 - Greater . z : , 5 : 2 3 3 : : 5 0 Total 160 231 430 1451 1617 1084 989 1315 1977 248 487 16 February 1980-1991, Gage 630 Percent Occurrence{x100) of Height and Period Height (m) Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- _2.9 3.9 4,9 _5.9 6.9 _7.9 _8.9 9.9 11.9 _13.9 _15.9 _Longer patere 0.00 - 0.49 9 q 9 44 61 44 87 79 79 26 =©105 : 543 0.50 - 0.99 52 96 175 419 471 314 497 689 1003 17 ~—-:166 9 3908 1.00 - 1.49 P OSG 46) 620253 s05eesSeuee ose 70 86201 : 3099 1.50 - 1.99 s : CS) ay Siete} IGE} is} ils} 2 52 96 ; 1343 2.00 - 2.49 : ; ‘ 79 ~=166 44 35 79 79 44 96 3 622 2.50 - 2.99 9 17 52 17 9 96 17 61 9 287 3.00 - 3.49 i 17 9 26 26 17 17 112 3.50 - 3.99 4 9 9 9 27 4.00 - 4.49 é 9 35 9 53 4.50 - 4.99 ; : : : 5 2 : : : 0 5.00 - Greater ; F : : : ‘ 9 : , . 5 5 9 Total 61 105 324 1424 1693 907 1072 1345 2051 243 760 18 March 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period Height (m) Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- 17.8) 3.8) G8) 9) _ 8) 7/8) fh.) —8),6) ILE) le) J'E.8) eee 0.00 - 0.49 7 3 7 15 37 37 103 29 125 66 118 : 544 0.50 - 0.99 7 74 169 434 420 398 611 700 898 118 221 F 4050 1.00 - 1.49 j 7 214 434 486 331 368 287 663 52 309 : 3151 150) = 1399 : : 24S COS eet Ole] OSteenl 5 5are43 66 103 ; 1295 2.00 - 2.49 : : ; 22 66 44 103 52 133 29 88 : 537 2.50 - 2.99 a 22 15 22 7 44 15 37 162 3.00 - 3.49 7 15 7 15 44 7 7 102 3.50 - 3.99 5 15 52 15 82 4.00 - 4.49 . ; 2 5 : f 7 15 15 : 22 i 59 4.50 - 4.99 ; 5 3 6 : : y ; 15 ; : ; 15 5.00 - Greater 5 rs é : A s . ; 2 : : : 0 Total 14 81 397 1148 1303 950 1324 1275 2232 353 920 0 (Continued) (Sheet 1 of 4) Bll Table B4 (Continued) April 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period Height (m) Me ee em PTETIOG ((S OG) le Seen eee nt ca Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- Bak) sie) SeIe6) ee) ae) ES) ie) BLS) ee) lei) leek) Ueatet-te 0.00 - 0.49 8 8 15 45 30 23. 264 203 151 75 75 : 897 0.50 - 0.99 68 173 249 430 618 497 859 844 1070 219 377 2 5404 1.00 - 1.49 : 8 106 226 407 309 369 324 294 53 143 2239 1.50 - 1.99 : : e158 58 90 106 106 166 23 83 : 890 2.00 - 2.49 38 60 8 45 60 45 23 8 : 287 25508-72299 : 8 23 30 15 30 23 15 : 144 3.00 - 3.49 30 15 23 23 91 3.50 - 3.99 8 30 ; 38 4.00 - 4.49 8 8 4.50 - 4.99 5 : : 5 8 o 3 4 8 5.00 - Greater ; : i ‘ i 4 5 5 ; ‘ , : 0 Total 76 189 370 897 1281 988 1726 1583 1779 416 701 0 May 1980-1991, Gage 630 Percent Occurrence{X100) of Height and Period Hei ght (m) sR Ress I eh ee SPO TETIOG (CSCC) EE Ss ea RC Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0-- E2299 A OPES OE GE O72 OBS ENO lS 59 59 palvonger pre 0.00 - 0.49 7 22 52 96 148 141 392 266 215 52 133 a 1524 0.50 - 0.99 22 192 377 42637 585 888 1214 888 681 104 215 : 5803 1.00 - 1.49 5 7 133 244 «333 207 370 215 # 266 15 74 5 1864 1.50 - 1.99 5 5 7 59 74 44 104 59 89 22 59 F 517 2.00 - 2.49 , , 3 15 44 52 7 30 7 22 22 5 199 2.50 - 2.99 - Fi i 22 7 7 7 7 15 7 2 72 3.00 - 3.49 7 7 14 3.50 - 3.99 " 0 4.00 - 4.49 ‘ é 5 2 . y 2 : 5 P 5 : 0 4.50 - 4.99 , z 5 ; 5 5 : ‘ : ‘ 0 5.00 - Greater 5 a f ‘5 ; 3 7 3 5 ‘ i ; 0 Total 29 = 221 569 1051 1206 1339 2094 1465 1265 237 517 0 June 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period Hei ght (m) Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- —2.9 3.9 4.9 5.9 6.9 7.9 8.9 _9.9 _11.9 _13.9 _15.9 _Longer ee 0.00 - 0.49 24 32 48 129 201 346 707 547 209 40 32 5 2315 0.50 - 0.99 48 217 354 651 723 683 1672 989 523 129 48 3 6037 1.00 - 1.49 : 8 88 225 177 177 201 = 105 96 ; 40 3 1117 1.50 - 1.99 . ‘ 16 56 105 56 32 16 96 i 48 ; 425 2.00 - 2.49 3 : A : 24 16 48 8 : : : : 96 2.50 - 2.99 ; 8 3.00 - 3.49 0 3.50 - 3.99 0 4.00 - 4.49 0 4.50 - 4.99 f ; : i 5 5 : F : 0 5.00 - Greater j : : 3 2 : i 5 : ; A 5 0 Total 72 257 ‘506 1061 1230 1286 2660 1665 924 169 168 0 (Continued) (Sheet 2 of 4) B12 Table B4 (Continued) July 1980-1991, Gage 630 Percent Occurrence{X100) of Height and Period Hei ght(m) Period(sec) Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- W728) SiG) ee) ei) ie) 7/8) RI) IG) ILS) _SISIAE) ei.) 0.00 - 0.49 8 16 47 86 203 320 1008 680 266 94 195 16 2939 0.50 - 0.99 31 148 336 703 906 805 1469 898 406 211 125 63 6101 1.00 - 1.49 z 16 63 195 227 86 125 39 39 : j : 1.50 - 1.99 : : 3 47 8 16 23 16 39 : : : 149 2.00 - 2.49 8 : : 8 Z 2 ‘ ; : 16 2.50 - 2.99 0 3.00 - 3.49 0 3.50 - 3.99 0 4.00 - 4.49 0 4.50 - 4.99 3 : : 2 0 5.00 - Greater ; 2 : d : s e : i 2 ; : 0 Total 39 180 446 1039 1344 1227 2633 1633 750 305 320 79 August 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period Height (m) Soe ree Period (Sec) es ee Total 2.0- 3.0- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 12.0- 14.0- 16.0- — 8) —_)n8) __ 418) —5.9 _6.9 _7.9 _8.9 _9.9 11.9 _13.9 _15.9 _Longer ans 0.00 - 0.49 23 23 54 107 146 192 583 507 353 77~=—-:100 : 2165 0.50 - 0.99 38 92 230 553 844 698 1266 867 821 153 315 38 5915 1.00 - 1.49 3 8 130 307 261 184 223 123 84 15 31 ‘ 1366 1.50 - 1.99 : 5 69 138 54 31 15 15 A 31 : 353 2.00 - 2.49 15 31 15 15 31 8 8 : 123 2.50 - 2.99 8 5 15 5 8 : 39 3.00 - 3.49 8 8 8 8 32 3.50 - 3.99 : 8 4.00 - 4.49 4.50 - 4.99 : ; % A 3 : : ‘ ; 5.00 - Greater 2 ; : 4 5 : 5 5 Z 3 ; : Total 61 123 414 1051 1436 1151 2141 1520 1320 253 493 38 September 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period Hei ght (m) A ee POPOU (SOC) one nee oe Se Total Dis Bs CS Ble BOS TOs Bile O.0>. NOM 10s Nats 16.0- —2.9 3.9 4.9 _5.9 6.9 7.9 8.9 _9.9 11.9 _13.9 _15.9 _Longer Basie 0.00 - 0.49 8 8 8 31 23 15 107 244 214 92 84 8 842 0.50 - 0.99 - 107 +176 405 534 588 893 779 1000 145 282 : 4909 1.00 - 1.49 , 8 84 466 466 313 496 237 328 92 160 8 2658 1.50 - 1.99 ; : 8 137 282 145 92 115 61 23. ~=—«:107 8 978 2.00 - 2.49 : 2 : 31 92 53 76 23 61 61 61 2 458 2.50 - 2.99 : : : , 46 23 8 : 8 8 : 93 3.00 - 3.49 F ‘ é 3 : 8 ; 8 8 8 8 : 40 3.50 - 3.99 : j A ; : : B I 8 8 8 3 24 4.00 - 4.49 : 4.50 - 4.99 ; 4 A ; : ; : 5.00 - Greater R ; 3 : 3 : 5 7 : 8 . 5 Total Sil 23 276 1070 1397 1168 1687 1414 1680 445 718 24 (Continued) (Sheet 3 of 4) B13 Height (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1.50 - 1.99 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total Height (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1.50 - 1.99 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total Hei ght (m) 0.00 - 0.49 0.50 - 0.99 1.00 - 1.49 1.50 - 1.99 2.00 - 2.49 2.50 - 2.99 3.00 - 3.49 3.50 - 3.99 4.00 - 4.49 4.50 - 4.99 5.00 - Greater Total Table B4 (Concluded) October 1980-1991, Gage 630 Percent Occurrence(X100) of Height and Period a ase a a PG TOG CS 2G) cee ere Ue eR 10.0- 12.0- 14.0- 16.0- 2W> So 05 B=. B= 7 Bolt. Sale AG) 8) G8) 8) TR) 778) LES) SI8) UL) _1eh..8) 1.9) 29 : ¢ : 44 73, 169 = 125 29 59 169 353 382 316 683 507 : 169 588 360 198 220 287 ZO 235 S75 l25 88 103 : 22 6118 =~ 162 66 81 37 96 29 59 29 7 7 : 7 22 7 7 58 59 367 1198 1316 999 1276 1198 492 November 1980-1991, Gage 630 Percent QOccurrence(X100) of Height and Period Longer nN RPNN™NE Ne NO N- MN ee LLL all casos Sone PE TETOG (SOG!) Kamei erates Rese me emt 10.0- 12.0- 14.0- 16.0- n 2a 0 =n 0= 39) 43 35 43-87 17 86 139 4.0- 4.9 26 364 260 17 667 5.0- 6.0- 7.0- 8.0- 9.0- 26 43 104 277 190 641 571 476 511 537 511 684 398 277 251 208 329 «4199 121 69 26 46121 «6121 = «113 35 : 9 35 9 17 : 9 17 43 : 9 9 : 0 9 ; : : 9 1412 1757 1342 1334 1169 95 606 268 104 26 43 35 9 1186 December 1980-1991, Gage 630 —5.9 _6.9 _7.9 _8.9 _9.9 11.9 _13.9 _15.9 477 Percent Occurrence(X100) of Height and Period _Longer 104 ase nah ee nes PET Od (SOG) sean ne sreeneaneny eS eee ee 10.0- 12.0- 14.0- 16.0- Ade So) C05 30> So) 70>. Soe: Pole 2259) 23.9 49 22559) 659) 79) 89) 99) SED 21309) 215.9 81 27 45 63 18 27. «108217 36 181 244 487 650 235 442 469 ; . 199 469 605 325 226 135 27 0 217—s 487 144 30 63 18 een cS Ome 17, 36 45 : ; 45 : 18 9 63 18 0 27 18 é 9 117. 208 533 1236 2040 902 992 992 B14 135 171 36 9 45 414 _Longer 36 45 (Sheet 4 of 4) Height, m 0 10% Ol 10° 10 10 Percent Greater Than Indicated Figure B2. Annual cumulative wave height distributions for Gage 630 B15 Height, m Figure B3. 110%: 10° 10 Percent Greater Than Indicated 1991 monthly wave height distributions for Gage 630 B16 10 Height, m 0 1Ona 10' 10° 10 Percent Greater Than Indicated Figure B4. 1980-1991 monthly wave height distributions for Gage 630 B17 Frequency of Occurrence, % Gage 630 _al Gage 111 xe on Gage 625 aA Gage 645 Figure B5. 1991 Gage 630 1980—91 Oe ZA lial noo __ Albedo Are Pei 7Pbon|_.aballbao ae ao __eaaeldan Gage 645 Annual wave period distributions for all gages B18 pbeee a oy eae % 20 20 Ls ; ss Jan y) _ doealia. 1 wee. re : Socesee | tlt ee Figure Bé. ‘gt er ee Sep “be ___aeddde Oct _ofabeodd.. Nov __ Agadgon a O 12 14 16 2 ® momez) ©) a @) Oot Ww (4) @mes 1991 monthly wave period distributions for Gage 630 Frequency of Occurrence, % 40 20 0 b> Be Ls Iss . __oeoodll.. ae Aug __ Afooto | .nedB Sep __ aG0000e0.4)_..cBolaben. Oct sosneeeg ck __ pfAeeedon Nov ttl __aAGE en Re Figure B7. 1980-1991 monthly wave period distributions for Gage 630 B20 Height (m) WWD -- oO Pigs SCS Ce, Cee a oOMOoOUOoOMOoOU 1980 through 1991 Average Persistence of H,, Height (m) WWM NM--—- oO oo fel eo ea oO Table B5 1991 Persistence of H,, for Gage 630 Consecutive Day(s) or Longer yA Sf ee us SAO Ws Wann de WO Meads 13 15 12 10 ©) 6 5 28 20 13 Qj} & 3 2 1 12 5 2 1 5 2 1 3 1 3 1 Table B6 Consecutive Day(s) or Longer ZS bo 3 CO F 8 UD AO WW We Wb We We IG. alr 18 16 15 14 12 11.10 Ot he OB le ee 1° > 3 2 1 ma iil © & 2 1 ale es = 1 5 2 2 61 1 1 B21 19+ 18 4 for Gage 630 19+ 4 SITY RELATIVE ENERGY DEN RELATIVE a. ek ; Ck ~ \) KY} : \) NY \) WALA HS WY) \ Nh ny — = SSS ~~ @ aa we nN or A \ ' " " ' 4 Ny tN i. >S SoS PSS SS SO SSS OSS Se ss SoS Sos >S oo oes SSeS SSeS if SSeS SSS Sees Ses Sse f} 5 ooZ dt LOSSSO SoS Carat AT 7 a ce aod Loss ee CS S SSS SOS OSS COSI 98 OTK LSE SES SPSS SS SSS SOS Se = Ses Sos 5 LYRES SOS SISSIES SOS SSeS eee 1 See LIFES SSS ESS SSE SSS SSSI OSSLOS Ss SSS OS SSS S27 CIPS OSS SS ce => LT Ty pe COS SS Loh >S SDSS aS ra LSS LOSSES B22 RELATIVE ENERGY DENSITY RELATIVE ENERGY DENSITY L27> Ning Lé/ LL7 CZISLF, LF a, Ue If MRS Figure B8. (Sheet 2 of 6) B23 RELATIVE ENERGY DENSITY RELATIVE ENERGY DENSITY SESS ees Se Figure B8. (Sheet 3 of 6) B24 Ny i : \) A AN DN nan NN My WANN DARN SNH AON ON i NK a> esse a Ss ~ wo wo Cr m nN ALISNIG ADYINF FAILV 1494 \) = <= NM MY NY My SS <<2 2o \) cose } NYavaueaiial RECN oO SON CHO ERR HE AREREE 2 NOCH NNN ye NNN ial RAN \) DORE ROR HL NAS KN oS ASSMAN is : AAAARNN YSERA A KH) > DOME R EL ¢ 2 AA Ny $2 KY =) WARY 2 & iif e = } aes nt o 0 ~ De) ALISNIG ADYINI FAILV 134 ZSES LFS <<] N = c=} ee Ww {\ eo > MS Ni = LAK) Nh) CAC ame NYY ONY NYAS = AYA NYY BAYAN) OOH NYY KYA 3 POY PAO RAY | NWA o NOLS NY o ‘ \ 1S ag C625 = oU NZ o ll =) oO w = (as w (Sheet 4 of 6) Figure B8. B25 RELATIVE ENERGY DENSITY RELATIVE ENERGY DENSITY m \ ‘ O-—-NWAUMNYIMOO eee LE roe $2 <2 < Ss SEPSIS SOS EO SESS ISS ZSEL Sosess SSO 4] =2 ooh moe SSS SSIES == eT 5 i SESS IEEE SSE SEES ea CLL ee He Ly) FSS SSS 225 Sa a LL SSOSLLTS PEE 9 <285L7S SSS FSS SESS SSSI SSO 16 0.1 EET gek : aero LSSESSO ESS ES SH FREQUER” 25 eee | 0 cf) c 0.36 SRS Zz Figure B8. Oo w a = (Sheet 5 of 6) B26 RELATIVE ENERGY DENSITY RELATIVE ENERGY DENSITY So oS eos ZS SseSe re cea SS OOK oesseset 19 SLOSS SOSH Figure B8. (Sheet 6 of 6) B27 Table B/ Wave Statistics for Gage 630 Pe eae eee oe) |) | ee ee eee = iaht : _Period _ ante _ oe __ Std. Std. Std. Std. Mean Dev. Extreme Mean Dev. Number Mean Dev. Extreme Mean Dev. Number Month mm -.m Date sec sec Obs. im m Wm Date sec sec Obs, Jan 1S OR, ane 9 8.0 2.5 61 Nod (a7/ 4.5 1983 8.1 2.7 1255 Feb 1.4 0.7 2.8 23 os ihad/ 25 Leen OFZ, 5.1 1987 8.4 2.6 1146 Mar 1e2o0rS 2.1 30 B02 Bots 118 ibee4 — (ae/ 4.7 1983 8.7 2.6 1358 Apr 1.0 0.6 3.5 20 7.9 1.8 120 1.0 0.6 5.0 1988 8.6 2.6 1327 May 0.8 0.5 2.6 19 7.8 2.9 122 0.9 O.5 3.3 1986 8.1 2.5 1351 Jun 0.9 O.5 olf 23 Bae alee) 106 0.8 0.4 2.7 1991 7.8 2.2 1244 Jul OS /mem One 1.3 30 Toe Boll 116 0.7 0.3 2.1 1985 8.1 2.4 1280 Aug 0.8 0.5 3.5 19 8.9 2.5 123 0.8 0.5 3.6 1981 8.2 2.5 1303 Sep Nod 8) 2.6 1 8.1 od 119 1.1 0.6 6.1 1985 8.6 2.6 1310 Oct 1.4 1.0 5.4 31 9.7 3.4 122 1.3 0.7 5.4 1991 8.8 2.8 1361 Nov 1.1 0.9 4.6 9 8.2 2.9 118 1.1 0.7 4.6 1991 7.9 2.8 1155 Dec 1.0 0.5 2.9 19 7.5 2.6 41 1.2 0.8 5.6 1980 8.2 2.9 1108 Annual 1.1 0.6 5.4 Oct 8.3 2.6 1191 1 0.6 6.1 Sep 1985 8.3 2.6 15198 B28 Height, m On FON FON FON FOND ROD & 13.5 7 9 1113 15 17 19 2123252729 1 3 5 7 9 1113 15 17 19 2123 25 27 29 31 Day of the Month = WN o oo Period, sec 3 So N oo 10 13.5 7 9 1113 15 17 19 2123252729 1 3 5 7 9 1113 15 17 19 2123 25 27 29 31 Day of the Month Figure B9. Time histories of wave height and period for Gage 630 B29 ce ie eee one otters : i : : t eee Ta Wr eke? P K : 3 ‘i safe jas, 2 4 Seer aia Form Approved REPORT DOCUMENTATION PAGE Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden. to Washington Headquarters Services, Birerorstntos Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302, and to the Office of Management and Budget, Paperwork Reduction Project (0704-0188), Washington, DC 20503. 1. AGENCY USE ONLY (Leave blank) | 2. REPORT DATE 3. REPORT TYPE AND DATES COVERED June 1993 Final report 4. TITLE AND SUBTITLE 5. FUNDING NUMBERS Annual Data Summary for 1991 CERC Field Research Facility; Volume I: Main Text and Appendixes A and B; Volume II: Appendixes C through E 6. AUTHOR(S) Michael W. Leffler, Clifford F. Baron, Brian L. Scarborough, Kent K. Hathaway 7. PERFORMING ORGANIZATION NAME(S) AND ADDRESS(ES) 8. PERFORMING ORGANIZATION REPORT NUMBER USAE Waterways Experiment Station, Coastal Engineering Research Center 3909 Halls Ferry Road, Vicksburg, MS 39180-6199 Technical Report CERC-93-9 9. SPONSORING/ MONITORING AGENCY NAME(S) AND ADDRESS(ES) 10. SPONSORING / MONITORING AGENCY REPORT NUMBER US Amny Corps of Engineers, Washington, DC 20314-1000 11. SUPPLEMENTARY NOTES See reverse. 12a. DISTRIBUTION / AVAILABILITY STATEMENT 12b. DISTRIBUTION CODE Approved for public release; distribution is unlimited. 13. ABSTRACT (Maximum 200 words) This report provides basic data and summaries for the measurements made during 1991 at the US Army Engineer Waterways Experiment Station (WES) Coastal Engineering Research Center’s (CERC’s) Field Research Facility (FRF) in Duck, NC. The report includes comparisons of the present year’s data with cumulative statistics from 1980 to the present. Meteorological and oceanographic data, monthly bathymetric survey results, samples of biannual aerial photography, and descriptions of 18 storms that occurred during the year are summarized in this report. The year was highlighted by a major storm (the "Halloween Storm”) in late October. Waves with 6-m significant height and periods exceeding 21 sec were measured 6 km from shore. This report is the 13th in a series of annual summaries of data collected at the FRF that began with Miscellaneous Report CERC-82-16, which summarized data collected during 1977-1979. These reports are available from the WES Technical Report Distribution Section of the Information Technology Laboratory, Vicksburg, MS. 14. SUBJECT TERMS Did in ivo volusies) 16. PRICE CODE 20. LIMITATION OF ABSTRACT See reverse. 17. SECURITY CLASSIFICATION OF REPORT OF THIS PAGE UNCLASSIFIED UNCLASSIFIED NSN 7540-01-280-5500 Standard Form 298 (Rev. 2-89) Prescribed by ANSI Std. 2739-18 298-102 18. SECURITY CLASSIFICATION | 19. SECURITY CLASSIFICATION OF ABSTRACT 11. (Continued). A limited number of copies of Volume II (Appendixes C through E) were published under a separate cover. Copies of Volume I (this report and Appendixes A and B) are available from the National Technical Information Service, 5285 Port Royal Road, Springfield, VA 22161. 14. (Continued). Meterologic research--statistics (LC) Oceanographic research--statistics (LC) Oceanographic research stations--North Carolina--Duck (LC) Water waves--statistics (LC) Destroy this report when no longer needed. Do not retum it to the originator.